Abstract: For the height and attitude control issues in the transition mode of TRUAVs (tilt-rotor unmanned aerial vehicles), the MPC (model predictive control) method is introduced into the height and attitude control loop of the rotor controller, and a hybrid control algorithm based on model calibration MPC and PID (proportional-integral-derivative) control is designed. The MPC controller and its proportion are iteratively optimized to improve the dynamic characteristics in the transition mode of TRUAVs. Firstly, a dynamic model of a tilting multi-rotor UAV (unmanned aerial vehicle) is established, in which the rotor/wing interference and model dynamic changes are considered as uncertain dynamics. Then, the uncertain dynamics are estimated offline, and combined with a model calibration MPC controller, and the height and attitude control algorithm for the transition mode is designed. On this basis, a controller proportion adjustment mechanism is designed to gradually and iteratively improve the accuracy and proportion values of the MPC controller. A simulation environment based on Matlab + X-Plane is established, and the control performance of the proposed control method is also verified through simulation flight. Finally, flight tests are conducted on the test prototype of a tilt tri-rotor UAV. By comparing the results with PID control algorithm, it is shown that the proposed control method can effectively improve the dynamic characteristics in the transition mode of TRUAVs.