The invention discloses a motion planning method for preventing leftward and rightward inclinations of a humanoid robot and a device using the same, which belongs to the technical field of the motionplanning of the humanoid robot. The method comprises the following steps: setting a compensation angle to a motor at a hip joint and a motor corner at an anklebone of a supporting leg respectively; and adding the corresponding compensation angle to planned angles of the motor at the hip joint and the motor corner at the anklebone of the supporting leg respectively. The device comprises a compensation angle setting module which is used for setting one compensation angle to the motor at the hip joint and the motor corner at the anklebone of the supporting leg respectively, and an adding module which is used for adding the corresponding compensation angle to the panned angles of the motor at the hip joint and the motor corner at the anklebone of the supporting leg respectively, wherein the motor at the hip joint and the motor at the anklebone are the motors axially arranged along the forward and the backward directions of the humanoid robot. The motion panning method effectively reduces the phenomenon of the leftward and the rightward inclinations when the humanoid robot is supported by a single leg, and improves the touchdown stability.