In power technology, the dispatching and monitoring system needs to collect a large number of equipment operational status information from the smart substation. This results in a large amount of work for information access and acceptance. The existing smart substation monitoring information automatic acceptance system only realizes the signal acceptance from the terminal to the main station, and cannot realize the closed-loop real-time transmission of the whole signal. At the same time, spectrum leakage and fence effects in substation monitoring will have a large impact on the results of the acquisition. Based on the IEC 61850 and multi-machine multi-network parallel checking theory, this paper researches an automatic closed-loop acceptance system for the monitoring information of intelligent substations, and at the same time proposes an efficient substation data monitoring method based on full-phase spectrum correction technology. Based on an actual engineering project in the power industry, a relevant simulation and experimental analysis are carried out on the proposed theory and method, and the effectiveness and feasibility of the proposed method is verified. This work is supported by National Natural Science Foundation of China (No. 51977039) and Science and Technology Project of State Grid Fujian Electric Power Co., Ltd. (No. 52130A16C07).