The invention provides an autonomous underwater vehicle (AUV) vertical plane under-actuated motion control method, which comprises the steps that: (1) initialization setting is performed on the AUV; (2) a top-layer control computer transmits a mission and finishes the global planning; (3) a motion control computer receives the feedback information of a sensor, performs control calculation by using a self-adaptive neuro-fuzzy inference system-based auto-disturbance rejection controller, and outputs a control command, namely an elevator angle delta s of the stern; (4) a steering engine executes the control command, finishes the coordination control of AUV depth and pitch attitude, and realizes the motion control under the AUV vertical plane under-actuated constraint; and (5) whether the mission is finished is judged, if the mission is finished, the data is saved and the voyage is ended, and if the mission is not finished, the control command is continuously calculated by the motion control computer. The AUV vertical plane under-actuated motion control method is suitable for the under-actuated, strong-coupling and complex motion relationship of the AUV in the vertical plane motion process, and can realize precise motion control.