The article initially presents the implementation principle of a specific nuclear power Reactor Trip System and elaborates on the composition of the total response time calculation of the reactor protection system. In consideration of the requirements outlined in regular test supervision, it raises the issue of testing the total response time of the Reactor Trip System during unit overhaul in the commercial operation stage. Based on actual site conditions and combined with multi-plant and multi-equipment comparison, a representative test plan with implementable conditions is developed. The article introduces the specific implementation method and Theoretical optimization method for calculating response time.