Abstract: In recent years, the large-scale integration of renewable energy sources such as distributed photovoltaic and wind power in rural areas has transformed the traditional unidirectional radial power supply model into a more complex bidirectional and multidirectional power flow. This transformation poses technical challenges to relay protection systems, including maloperation and failure to operate. This study addresses the optimization of relay protection coordination in rural power grids with multiple power sources. A comprehensive mathematical model integrating photovoltaic, wind, and traditional power sources is developed. An improved particle swarm optimization-based multi-objective protection coordination optimization method is proposed, which also optimizes reliability, selectivity, speed, and economic efficiency.Simulation results show that with multi-source integration, the short-circuit current variation rate increased by 58.6% and the protection range changed by 31.5%. After applying the optimized algorithm, the success rate of protection coordination improved to over 95%, representing an 18.7% improvement compared with traditional methods. This study provides a theoretical basis and technical solution for the intelligent configuration of relay protection in rural power grids, with significant engineering value for promoting the integration of distributed power sources and enhancing power supply reliability.