The invention discloses a double-layer bag making machine and a bag making process thereof. The double-layer bag making machine comprises a frame body, an upper-layer bag making device, a lower-layerbag making device and a shearing device, wherein the upper-layer bag making device is formed by an upper-layer feeding device and an upper-layer gluing device; an upper-layer detection device is arranged between the upper-layer gluing device and the upper-layer feeding device, and comprises a first electronic eye, an upper-layer shielding curtain and an upper-layer net rack; the upper end of the upper-layer shielding curtain is fixed onto an upper cross beam of the frame body; the lower-layer bag making device is formed by a lower-layer feeding device and a lower-layer gluing device; a lower-layer detection device is arranged between the lower-layer gluing device and the lower-layer feeding device, and comprises a second electronic eye, a lower-layer shielding curtain and a lower-layer netrack; the upper end of the lower-layer shielding curtain is fixed onto a middle cross beam of the frame body; and the upper-layer gluing device and the lower-layer gluing device are connected with the shearing device. The double-layer bag making machine provided by the invention can be used for making two small bags at a time without the need of the participation of multiple people, so that the production efficiency is improved, the manpower is saved, the cost is reduced, and the structure is simple and applicable.