Ureteral flexible ureteroscopy is suitable for the treatment of which diseases: 1, extracorporeal shock wave lithotripsy (ESWL) localization difficulties, X-ray negative renal stones (<2cm); 2, ESWL residual lower renal calyceal stones; 3, embedded lower renal calyceal stones, the effect of ESWL treatment is not good; 4, hard stones (such as calcium oxalate stones, cystine stones, etc.), which is not conducive to the treatment of ESWL; 5, extreme obesity, severe spinal deformity, ureteral stones or renal stones that make it difficult to establish percutaneous renal access; 6, stones in the diverticular chamber of the renal calyces with calyceal neck stenosis; 7, embedded upper ureteral stones; 8, ureteral stones in combination with renal stones; 9, upper ureteral stenosis, dilation of the ureter under direct visualization or incision of the stenosis with a laser; 10, endoluminal resection of localized low-graded and low-staged upper urethro-uroepithelial tumors; 11, for the more extensive Limited upper urinary tract bleeding under direct vision electrocoagulation hemostasis. Ureteroscopy is used for diagnosis: 1, from the upper urinary tract hematuria localization diagnosis; 2, urine exfoliative cytology examination is positive; 3, filling defects in the contrast examination; 4, upper urinary tract epithelial tumors endoluminal treatment and follow-up; 5, unexplained renal colic; 6, unexplained hydronephrosis and ureteral stenosis.