Abstract: Aiming at the problem that the time threshold and open-close sensitivity of the first impact signal of trigger/delay grenade fuze need to be examined and detected in qualification test, the open-close function of trigger/delay grenade fuze was evaluated by developing test equipment and designing test scheme. By analyzing the structure and principle of the trigger/delay fuze, the critical condition for the reliable closure of the crash switch in the fuze was determined. Combining with the time threshold requirements stipulated by the product performance index, a device development scheme based on PLC program to control the accurate control of the whole process from opening the grenade safety grip to falling to the concrete floor was proposed, which ensures the fall height of the grenade and the collision time of the concrete floor, and effectively solve the technical problem that the open-close time threshold and the openclose sensitivity of the trigger/delay fuze could not be tested.