The clinical incidence of urinary stones in pregnancy is about 1/2500 to 1/1500, and Gorton et al. reported that the incidence of urinary stones in pregnant women is 0.04% to 0.50%, because most of the patients are only symptomatic, so the true incidence of stones in pregnancy is not clear. It has been suggested that changes in the anatomy of the urinary system during pregnancy (e.g., hormonal principles of ureteral dilation and changes in ureteral patency) and changes in calcium phosphate metabolism may be responsible for the formation of urinary stones in pregnant women. It is generally believed that during pregnancy, due to the influence of progesterone levels, the smooth muscle tone of the urinary system decreases, the ureteral wall thickens, peristalsis decreases, and the urinary flow is slow, which is the main factor in the occurrence of urinary stones. Stones obstruct the ureter, causing smooth muscle spasm in the wall of the ureter leading to fluid accumulation in the ureter and a sharp increase in intrarenal pressure, resulting in renal colic. During pregnancy, the level of progesterone increases, the peristalsis of ureteral smooth muscle slows down, the ureteral wall thickens, and the uterus compresses the ureter, which often leads to ureteral fluid accumulation and can also induce renal colic. The stones and fluid increase the chance of infection in the upper urinary tract, and inflammatory irritation is another factor that causes renal colic. Therefore, antibiotics should be used to control the infection according to the bacterial culture and drug sensitivity test in a timely and correct manner. At the same time, attention should be paid to the effect of drugs on the fetus, and the principles of clear indications, reliable efficacy, safety to the fetus, and strict control of dose and time should be followed. The general principles of treatment for ureteral stone emergencies during pregnancy are to relieve obstruction, prevent and control infection, and ensure the safety of mother and child. It is difficult for antibacterial drugs to reach the lesion because of the damage of renal pelvic hypertension and renal function, and the effect of simple application of antibiotics to control the infection is poor. Therefore, while actively correcting the general condition, the infection can be controlled and renal function can be saved by releasing the obstruction and unobstructed drainage of urine as early as possible. The traditional treatment of pregnancy combined with ureteral stone emergencies is open surgery or cystoscopic indwelling ureteral catheter drainage. The former is more invasive, has more complications, and endangers the safety of mother and child; the latter is more difficult to operate under non-direct vision and sometimes retrograde placement of the guidewire. Due to the poor general condition of these patients, any invasive surgical treatment has a high risk. In principle, the surgery should not be too large and should be minimally invasive. With the development of endoluminal technology and the accumulation of experience in endoscopic operation, ureteral stones combined with pregnancy are more likely to be treated with minimally invasive techniques. Ureteral double J-tube placement plays an important role in relieving renal colic in pregnancy where conventional antispasmodic and analgesic treatment is ineffective, relieving urinary tract obstruction and saving impaired renal function. In cases of urinary stone obstruction with fluid accumulation and infection, which is not well controlled by medication, double J-tube placement can be chosen as soon as possible. In our group, eight patients had double J tubes placed via cystoscopy or ureter under local anesthesia due to frequent attacks of renal colic and urinary tract infection. Postoperatively, all patients experienced pain relief and no preterm abortion. After the placement, we combined the treatment with bacterial culture and drug sensitivity test, so that the urinary tract infection could be effectively controlled, and the position of double J tube was normal on ultrasound review, and the hydronephrosis was reduced, which indicates that the placement of double J tube is safe and effective for the treatment of urinary tract infection complicated by ureteral stone during pregnancy. In recent years, with the continuous improvement of ureteroscopy and the application of holmium laser for lithotripsy, the technique of ureteroscopic endoluminal treatment has been increasingly improved, and several scholars have reported the use of ureteroscopic lithotripsy for the treatment of ureteral stones in pregnancy. Holmium laser has a wavelength of 2100 nm, which can safely and effectively crush all urinary stones, and has a shallow penetration depth of less than 0.5 mm. Lifshitz concluded that ureteroscopy is the treatment of choice for ureteral stones in pregnancy because it is confined to the lumen of the urinary tract. Therefore, the ureter is relatively wide during pregnancy, and as long as the procedure is performed gently, the surgical trauma and the impact on the pregnant woman and the fetus are minimal, and ureteroscopy is not made more difficult by the altered physiological anatomy of the pregnant woman. In our group, Holmium laser lithotripsy under ureteroscopy was used in 12 patients, and the pregnancy was safely passed with satisfactory results. Percutaneous nephrostomy is a treatment method that can effectively drain hydronephrosis and rapidly reduce intrarenal pressure. We believe that percutaneous nephrostomy can be considered in patients with ureteral stones in pregnancy combined with urinary tract infection in the following cases: 1. Intractable renal colic, which is unbearable for the patient. 2, urinary stones combined with infection, persistent fever and poor anti-infection treatment. 3, Review of ultrasound, hydronephrosis aggravated in a short period of time. 4.Bilateral ureteral obstruction or solitary renal obstruction affects renal function. Postoperative fistula often causes obstruction due to secretions or tissue debris, therefore, the inner diameter of nephrostomy tube should be thicker. In conclusion, minimally invasive treatment of ureteral stones combined with infection during pregnancy should be chosen as early as possible.