Abstract: In response to the application requirements of power transmission and distribution inspection and emergency repair vehicles in mobile operation scenarios, a domestically produced vehicle-grade intelligent on-board gateway based on the Beidou system was designed and implemented. This gateway aims for autonomous control and adopts a domestic vehicle-grade dual-core processor (MCU + MPU architecture), a national encryption security chip, and a Beidou multi-frequency module to build a hardware platform. It achieves comprehensive domestic substitution and performance optimization from the chip to the system. The test results show that the positioning accuracy is ≤ 1 m, the communication delay is≤ 50 ms, and the data transmission success rate is ≥ 99.9%. In practical applications, the positioning error converges to 0.8 m, the emergency response time is compressed to 5 s, and the data upload efficiency is increased by 40%. The innovation point of the research lies in the construction of a software and hardware integrated architecture based on domestic chips, breaking the dependence of power mobile operation equipment on imported components; at the same time, multi-source fusion positioning and short message communication are deeply integrated into the vehicle-grade gateway, ensuring the reliable transmission of emergency instructions even in the absence of public network signals.