With the rapid development of electric power industry in China, in order to meet the increasing demand of power supply reliability, improve the operation efficiency of power grid switching, and reduce the safety risk caused by misoperation, a scheme of "one key" operation based on the integrated platform of master control station is proposed (hereinafter referred to as "sequence control"). This paper first introduces the frame of the scheme, the sequence control flow, and then introduces the judgment method of the locking signal, mainly including the partition of the interlock signal, the division of the signal within the interval. The generating flow of lock knowledge base and rule base and the processing logic of inference machine are introduced. Finally, the application effect of this scheme in actual scene is introduced. The operation function of "one key" sequence control can realize the operation of cross-station lines to cold standby interrotation and the completion of complex operations such as bus inversion, etc. The whole operation process does not require additional manual intervention, which greatly reduces the time of power outage caused by manual operation and improves the reliability of power supply. This work is supported by National Key Research and Development Program of China (No. 2017YFB0902600).