The invention provides a steamed bun leavening, steaming and airing all-in-one machine. The steamed bun leavening, steaming and airing all-in-one machine comprises a dough leavening area, a steaming area, an airing area and a main power system which are connected to be a whole. A plurality of hanging basket assemblies for bearing steamed buns penetrate the dough leavening area, the steaming area and the airing area. The hanging basket assemblies are driven by a conveying chain to perform sequential and continuous cycle operation. According to the all-in-one machine, the steamed bun leavening and steaming process is continuous and unmanned, produced steamed buns are very stable in quality, the guarantee period is prolonged greatly, and the taste is unique. The machine is well welcome by steamed bun production enterprises, and the products produced by the machine are well welcome by consumers.