The processing of deviation power is a key link in the settlement of power transactions across provinces and regions.Firstly, the deviation settlement models of typical power markets at home and abroad is summarized, and then the three commonly used methods for allocation and settlement of deviation power to summarize their advantages and disadvantages are analyzed. And the problems of the current deviation settlement method with the development of the southern regional market are analyzed. In order to connect well with the spot market settlement mechanism and give full play to the role of market pricing, a separate pricing and settlement method for offset power is proposed, and the design of offset pricing and offset cost allocation mechanism is given. Finally, according to the settlement requirements of different development stages of the southern regional market, the reasonable selection of deviation settlement methods is put forward, and the prospect of how to improve the inter-provincial and inter-regional settlement mechanism of the southern region is expected.