The invention provides a perianal postoperative closed double-cavity irrigation negative pressure drainage device. The perianal postoperative closed double-cavity irrigation negative pressure drainage device comprises a main irrigation drainage device, wherein the main irrigation drainage device comprises a main irrigation tube and a main drainage tube. Compared with the traditional single main drainage tube, the device has the advantages that medicine change in the operative area can be avoided within at least one week after the operation, a few patients have pain, the device is close to the wound of the patient, and the device is convenient for full irrigation and drainage and can achieve the effects of enabling necrotic tissues in the operative area to be timely irrigated, dropped and attracted to discharge, promoting healing of the operative area, reducing the re-infection probability of the operative area and reducing mental stress, depression and other psychiatric disorders of the patients caused by pain. The main drainage tube penetrates through an inner cavity of the main irrigation tube; an interlayer between the inner wall of the main irrigation tube and the outer wall of the main drainage tube is a main irrigation chamber; the inner cavity of the main drainage tube is a main drainage chamber; a main spherical head is arranged at the front end of the main irrigation tube and comprises a main spherical outer wall and a main spherical inner wall; the rear end of the main spherical outer wall is connected with the front end of the main irrigation tube together; and the rear end of the main spherical inner wall is connected with the front end of the main drainage tube together.