Compared with the traditional substation, the system has added the process layer equipment merging unit and the intelligent terminal, which causes the time of the protection equipment to move slowly. In this paper, a single interpolation sampling algorithm is proposed to combine the synchronous sampling algorithm with the interpolation algorithm. Based on synchronous state adaptive adjustment sampling algorithm, the processing delay of the internal sampling data is reduced. The CPU plug-in of the intelligent terminal is improved and the GOOSE multicast filtering and network is completed by FPGA. The function of the winding storm, CPU is responsible for the reception and transmission of GOOSE, and the MOSFET photoelectric coupling relay is used as the starting relay, and the exit time of the intelligent terminal is reduced by the optimization design. On this basis, a new process layer device is developed, and the dynamic model simulation and static model simulation are compared. The simulation test results show that the newly developed process layer device can reduce the 3 ms before optimizing the whole action time of the line protection device, and can meet the whole group action time of the GB/T-14285 standard for the relay protection device. This work is supported by Science and Technology Project of State Grid Corporation of China (No. 52020116000L).