Chinas social and economic growth is steadily increasing, and the demand for electricity is also rising, which has put forward higher requirements for electricity production and its power supply system In this context, technological innovation in relay protection and communication equipment is crucial. This paper focuses on the research and practical application of direct connection technology between relay protection and communication equipment optical ports. Through in-depth comparative analysis of the practical application of dedicated channels and multiplexing channels in fiber optic communication equipment, the significant differences in data transmission distance between the two are revealed. In addition, from the perspective of technological integration, the paper explores in detail the interface relationship between communication and protection equipment and its core role in substations, in order to provide strong support for promoting the continuous progress of secondary technology in the power grid