Objective To investigate the microanatomic basis of thepudendalthigh flap and provide the anatomic basis for clinical application. Methods Skin microdissection of the pudendal regions was performed on 11 adult cadavers (22 sides). Then, the clinical way was simulated to obtain the flaps, and the vessels and nerves contained in them were surveyed. After that, the tissues in the deep part were dissected, and the vessels and nerves were traced back to their origins. The notes were taken. Results The blood supply to the pudenal regions was plentiful and constant. The initiation point of the superficial external pudendal artery was 2.14+ 0.23 mm in diameter; one branch of it was the inguinal branch and the other branch was the perineal branch. Their diameters were 1.38+0.34mm and 1.21+0.24 mm. The initiation point of the posterior labial or scrotum arteries was 1.13+0.24 mm in diameter, and the lateral branch was 0.67+0.33 mm in diameter. The anterior cutaneous branch of the obturator artery was 1.68+ 0.11 mm in diameter. The position of all the blood vessels was relatively constant, especially the external pudendal artery and the lateral branch of the posterior scrotal artery. Many of the blood vessels passed through the areas of the pudendum and the thigh, anastomosed with each other. Three groups of the vascular net passed through the upper, middle and lower parts of the flap. Three main groups of the innervation were as the following: the ramus femoralis nervi genitofemoralis, the cutaneous branches of the ilioinguinal nerve, and the postnerve of the scrotum or the labia vulvae. Conclusion The pudendalthigh flaphas an abundant blood supply, and its dissection is convenient with an easy incision; the donor site is covert. The pudendalthigh skin flap has the following advantages for the sexual organ reconstruction: the skin flap can have a good sensation and a good shape, and the operative procedure is easy to perform.