The damage threshold measurement device is an important technical indicator of high-power laser technology, which is mainly used for the development and testing of high-power laser optical components. The synchronous trigger module serves as a controller for controlling the timing between modules, and is one of the key technologies in the development of damage threshold devices. A synchronous trigger module and method for laser damage threshold measurement device were introduced. A hardware solution based on field programmable gate array (FPGA) as the main control chip was designed. By setting synchronous trigger parameters through the upper computer control software, the width of each output synchronization signal and the timing between each signal were controlled, which could greatly improve the accuracy and efficiency of synchronous trigger. Through experimental verification, the adjustment accuracy between synchronous pulse signals is 2 ns, and the minimum width of synchronous pulse signals is 10 ns, which meets the needs of laser damage threshold measurement devices.