In actual engineering and simulation research, it is found that the DC commutation failures may occur when the AC fault is removed, which worsens the recovery performance of the system, and even leads to DC blocking in serious cases. Firstly, the mechanism of commutation failure during AC fault removal is analyzed, and it is concluded that the forward shift of commutation voltage and high DC current are the main factors causing the commutation failure. Then, on this basis, the influence law of AC fault and fault duration on this commutation failure is studied; Finally, according to the evaluation of commutation voltage area, an improved strategy to suppress commutation failure at fault removal moment is proposed, and the simulation is carried out based on CIGRE HVDC standard model. The simulation results show that the proposed strategy can effectively suppress the occurrence of commutation failure during fault removal. The research conclusion can provide ideas for the suppression strategy of commutation failure at fault removal moment.