To achieve the goal of carbon peaking and carbon neutrality, it is urgent to build a new power system with renewable energy as the main body, characterized by clean energy supply and electrification of energy consumption. Considering the intermittency and randomness of wind-solar power, as well as the energy storage and flexibility of pumped storage power stations and power-to-hydrogen, a short-term production simulation model of wind-PV-hydrogen-pumped storage zero carbon power system is established based on the stochastic programming theory. In the proposed short-term production simulation model, on the basis of meeting the total demand of flexible hydrogen load, the short-term production simulation is implemented, including electricity-hydrogen production schedule, reserve capacity, pumped storage-water discharge power output and wind-solar curtailment, with the goal of maximizing green on-grid electricity. Taking Zhangbei zero carbon power system of China as an example, many operation scenarios are established to simulate the proposed model. The simulation results show that the proposed model can effectively simulate the on-grid scheme situation of green power in which the system deals with the randomness of wind-solar output in any output scenarios of wind-solar power scene set. The flexible hydrogen load and the pumped storage power station can effectively promote wind-solar energy accommodation and increase the comprehensive benefit of the combined system.