Urolithiasis is a common disease in urology. With the continuous progress of science and technology, the treatment of kidney lithiasis has undergone revolutionary changes, and the previously commonly used open surgical lithotomy method has been gradually eliminated, and replaced with less traumatic treatment methods. Percutaneous nephroscopy can theoretically treat the vast majority of kidney stones, especially in the treatment of kidney stones \> 2 cm, it is widely used. With the development of ureteroscopy technology, the adaptation of ureteroscopy for the treatment of kidney stones has been expanding, and people have gradually paid attention to it with less damage and higher safety. This study aims to evaluate whether the efficacy and safety of soft ureteral lithotomy in the treatment of 2-4cm kidney stones is equal to that of percutaneous nephrolithotomy through prospective randomized controlled clinical trials, so as to provide more choices for physicians and patients, and provide theoretical basis for the standardization of clinical practice and the rationality of treatment.