The invention discloses a gear pair structure walking robot. The gear pair structure walking robot comprises a motor, a driving gear, a first driven gear, a second driven gear, a third gear, a fourth gear, an internal supporting frame, a first rotary shaft, a second rotary shaft, an external supporting plate and supporting soles; the motor drives the first rotary shaft and the second rotary shaft to rotate in the front direction and the opposite direction through the driving gear, the first driven gear and the second driven gear and accordingly drives the third gear and the fourth gear to drive the external supporting plate and the foot soles to perform arc back and forth movement within a certain angle through the third gear and the fourth gear; accordingly vertical and back and forth movement of the foot soles of a robot is achieved. The gear pair structure walking robot has the advantages that the structural size is small and exquisite, machining and installation of parts are convenient, and the above parts have no special requirements for materials.