The invention provides a shoe. An air valve mounting through hole is formed in the position close to the shoe sole on the back surface or the lateral surface of a main heel of the shoe. An inward-protruded one-way valve is arranged on the air valve mounting through hole. The inward-protruded conduit of the inward-protruded one-way valve passes through the air valve mounting through hole and extends inside the main heel. A height-increasing insole is arranged on the shoe sole and has a certain thickness at the heel part of the height-increasing insole. An elastic air sac is arranged at the heel part of the height-increasing insole. A rear air guide hole is formed on the back surface of the lateral surface of the elastic air sac. A front air guide hole is formed forwards on the elastic air sac. An intermediate one-way valve is arranged inside the front air guide hole. The air flow control directions of the two one-way valves are the same. A main heel fixing seat is also arranged at the back part of the shoe. The air valve mounting through hole penetrates, from outside to inside, the vertical sheet and the main heel of the main heel fixing seat. The inward-protruded conduit of the inward-protruded one-way valve extends to the inner side of the main heel and then engages with the rear air guide hole of the height-increasing insole. The shoe has the advantages of good ventilation effect, compact structure, good appearance, height-increasing effect and simple production, and is applicable to the large-scale production.