There is a transient overvoltage problem at the sending end grid during a commutation failure in an HVDC transmission system. We therefore propose a transient overvoltage suppression method of the sending end grid based on virtual resistance control of the rectifier station. The reactive power dynamic characteristics at the AC side of the rectifier station during the commutation failure and the mechanism that contributes to the transient overvoltage of the sending end grid is analyzed. By analyzing the key DC control variables that affect the transient overvoltage and combining the commutation margin boundary conditions, a sending end grid transient overvoltage suppression controller based on virtual resistance is designed. The controller can dynamically adjust the trigger delay angle of the rectifier station according to the transient overvoltage level of the sending-end power grid to achieve the transient over-voltage suppression target. The simulation example shows that the proposed control method can effectively suppress the transient overvoltage of the sending end grid during commutation failure by coordinating the virtual resistance link with the conventional constant current control. This work is supported by the Science and Technology Project of the Headquarters of the State Grid Corporation of China (No. 52170221000U).