The utility model relates to the technical field of model airplanes, and discloses a
space shuttle model undercarriage mechanism which comprises two first shells, second fixing plates are fixedly connected to the left end and the right end of the front side of the first shell on the rear side, a self-
locking mechanism is rotationally connected to the outer walls of the second fixing plates, and a third fixing plate is rotationally connected to the bottom end of the self-
locking mechanism. A hatch cover is fixedly connected between the adjacent rear sides of the two third fixing plates, and a first fixing plate is fixedly connected to the middle of the front side of the first shell on the rear side. In the utility model, the motor is started to output power, the first rotary joint is driven to rotate through the transmission connecting rod, the wheels are driven to turn over to touch the ground, and after the transmission connecting rod is in place, the self-
locking mechanism at the second rotary joint locks and prevents reverse movement, so that the transmission precision and the scene reduction degree are improved, the stable unfolding posture of the undercarriage is kept, and the cabin cover of the undercarriage is simultaneously opened in the process; and the process is ensured to be smooth and unobstructed, so that daily use requirements of operators are met.