A new method to evaluate multi-regional new energy accommodation capability is proposed based on mixed integer optimization, which combines the advantages of the traditional peak balance analytical method and the production simulation method. The new energy accommodation capability in each region is considered as a decision variable. Considering different operation constraints such as new energy output characteristics, various types of generator characteristics, transmission, heating unit, the proposed model can effectively evaluate the maximum capacity of new energy that can be installed under the requirement of a certain power curtailment ratio. Based on the proposed model, the new energy integration capability of China in 2020 was evaluated, the base scenario, the low thermal power flexibility scenario and the high power flow scenario were investigated and the relevant suggestions for promoting new energy consumption were given.