With the increasing of the number of main transformers, the 330 kV receiving-end power grid increasingly interconnected, the short-circuit current level of Northwest power grid increases year by year, the network partition becomes an important measure to limit the short-circuit current of the receiving-end power grid. Through the analysis of the characteristics of the summary in Shaanxi, Gansu and Qinghai region typical 750/330 kV receiving-end power grid and considering main transformer units, main transformer capacity and line length factors, this paper constructs the receiving-end grid zoning equivalent model for single station independent power supply, two-station partition or three-station chain partition. Through the analysis of short-circuit current level of typical partition model and main transformer load rate in partition, it determines the upper limit and lower limit of the partition of main transformer units, and proposes that 750/330 kV receiving end grid partition should be 2 to 3 seat 750 kV substation, about 4 to 6 main transformer with a piece of 330 kV power grid reasonable partition scale. Finally, through Qinghai actual 750/330 kV power grid, the effectiveness of the proposed 750/330 kV receiving-end grid partition scale is verified.