It is normal for the urine line to become flat after urethral stone surgery. After urethral surgery, due to the surgical instruments and surgical damage to the urethra, there will be edema, and there will be a short period of time for the urine line to become flat. Usually about a week after surgery will gradually return to normal. If the urine line has not returned to normal after two months, it is abnormal and treatment is needed at this time. If the urine line continues to become thinner after more than a week, it is more likely that the surgical damage in the urethra has caused narrowing of the urethra, including the formation of scarring in the urethra, which thins the original urethra and thus affects the shape of the urine line. Generally, the shape of the urethra will become fixed two months after the surgery. If the urethra is still flat and accompanied by hydronephrosis or decreased renal function, surgery is recommended to remove the urethral stenosis. If the urine line still fails to return to normal two months after the surgery, with difficulty in urination or even with hydronephrosis or renal insufficiency, it is necessary to improve the diagnosis by imaging or urethrocystoscopy, and according to the situation, urethral dilatation, endostomy or even surgical resection of urethral stenosis. Patients with long-term postoperative abnormalities need to consult a doctor for timely examination and treatment.