In recent years, transanal total mesorectal excision (taTME) has become one of the focuses of colorectal surgery, but it still faces some controversial problems that have not been solved, such as urethral injury as a typical complication. This paper, from the perspective of urological and rectal surgery respectively, elucidates the current research progress on the anatomy between the rectum and urethra. From the perspective of urethral anatomy, the main structure involving urethral injury in taTME surgery is the rectourethral muscle, which actually is part of the longitudinal muscle of the rectum from the perspective of rectal anatomy. Summarizing existing research results, the authors propose a new perspective about the key anatomical structure of hiatal ligament. As a matter of fact, hiatal ligament is the branch of longitudinal muscle of the rectum which circles the rectum, and the thickest part is at the center of the front and back respectively, then becomes thinner gradually to the 1 o'clock and 11 o'clock position. The front part of the hiatal ligament is just named as rectourethral muscle for urology surgery. On this basis, when taTME surgery is performed, it is recommended to follow the principle of " lateral first, center later" , that is, the thin lateral parts of hiatal ligaments is separated first, then the thick central parts after entering the familiar space. If necessary, the position of urethra and prostate can be confirmed through digital rectal examination, fluorescence catheter or other navigating methods. This paper aims to promote further development and popularization of taTME by introducing relevant anatomy of taTME surgery and various methods to avoid urethral injury.