The randomness and volatility of new energy cause difficulties in grid-connection and consumption. Based on the Equivalent Energy Function Method, a probabilistic production simulation algorithm is proposed, which helps to coordinate planning of new energy and conventional energy. Firstly, based on the multi-state model, segmented simulation is proposed to embody the timeliness of new energy, and the traditional Equivalent Energy Function Method’s shortcoming of losing timing information is overcome. Secondly, based on the system reliability indices (LOLP and EENS), two indices describing the system’s regulation performance are proposed, which includes Loss of Regulating Capacity Probability (LORCP) and Expected Regulating Energy Not Supplied (ERENS). Finally, the IEEE RTS-86 is applied to verify the accuracy and feasibility of the proposed algorithm and study the impact of wind and solar on system reliability and regulation. This work is supported by Science and Technology Project of China Southern Power Grid Co., Ltd (No. 031200KK52160003) and International (Regional) Cooperation and Interexchange Project of National Natural Science Foundation of China (No. 51761145106).