The unmanned underwater vehicle (UUV) path tracking control provides the important technical foundation for various civilian and military applications of UUV. Aiming at the underactuation, nonholonomic constraint and model nonlinearity in the path tracking control of UUV, an UUV vertical path tracking controller is designed based on the nonlinear continuous model predictive control algorithm. The vertical motion model of UUV is established, and the prediction model of UUV system is given based on state space model. According to the given performance index, the Taylor series expansion and Lie derivative are used to solve the optimal control law under the continuous time state, the underactuated UUV vertical path tracking control is achieved. A simulation experiment was carried out, the result proves the effectiveness of the design of the vertical path tracking controller.