Abstract: Currently, the research on the load characteristics of grid fault ride-through of doubly-fed induction generator（DFIG）based wind turbines is insufficient. Firstly, based on the spring-damping-mass modeling method, response models of DFIG based wind turbines for the load of drive train shafting and the side-to-side vibration of tower are established, and then the analytical expressions of the system natural resonance frequency and damping coefficient are obtained. The theoretical analysis results show that the grid fault ride-through process may cause torsional vibration of the drive train and the side-to-side vibration of tower.Secondly, a co-simulation model of GH Bladed and MATLAB is established, and the effects of symmetrical and asymmetrical grid fault ride-through processes on load characteristics of the drive train shafting and tower based on the co-simulation model are studied. Simulation results verify the correctness of the theoretical analysis. Finally, the influence of different active power recovery strategies on the load of wind turbines is further analyzed. The research results show that the over-fast active power recovery rate will significantly increase the load of wind turbines. Therefore, the principle of"mechanically friendly"grid fault ride-through control for wind turbines is further proposed.