Under the background of constructing a unified national electricity market, the integration between provincial markets has been deepening. When organizing inter?provincial spot trading, it is necessary to accurately delineate the regional equivalent values of the node network, taking into account each province's information security and limited computing power. These equivalent values are then embedded into the clearance model of inter?provincial spot trading.use congestion power transfer weights of internal nodes towards the price zone have time?varying characteristics and are The transfer distribution factor that can meet the requirement of computing efficiency. In this paper, we first crucial for the accuracy of the clearance calculation. Traditional methods often use a daily fixed mean value as an approximation, which is no longer sufficient to meet the requirements. The increasing proportion of renewable energy exacerbates the uncertainty of system operation, manifested in frequent changes in power flow transfer and an increase in volatile congestion scenarios, which will further affect the effectiveness of traditional fixed regional equivalent methods. This paper proposes a price zone division and approximation calculation method adapted to a high proportion of renewable energy. Firstly, based on consensus clustering, typical congestion scenarios in the electricity market are constructed, and a price zone equivalent partition method is proposed. Secondly, an improved calculation method for power transfer weights of internal nodes towards the price zone is presented. The problem of reduced calculation accuracy due to time?varying power injections is avoided by classifying node characteristics and calculating the power transfer weight matrix accordingly. Finally, the effectiveness of the proposed model is verified through validation using the IEEE 118?node case.