The invention relates to a liner stitching machine of a leather cotton-padded cap for military use, comprising a frame of the liner stitching machine of the leather cotton-padded cap, a machine head arranged on the frame, a stitching device arranged at the front of the machine head, a feeding device and an assistant trim device arranged on the frame. A transmission mechanism is arranged in the machine head. The liner stitching machine of the leather cotton-padded cap for military use has regular stitching line, orderly stitching array, and improved product quality. Compared with the manual stitching of the liner which needs a quarter to finish the work, the machine of the invention can finish the stitching in 1 to 2 minutes, thereby greatly enhancing the production efficiency, saving the labor force and reducing the production cost. The machine of the invention can enhance the work efficiency, and is suitable for the requirement of large batch production.