Beidou Bontec successfully undertakes the time synchronization construction tasks for the North Sea and East Sea Fleet of the Chinese Navy. It covers many key nodes such as Qingdao, Weihai, Ningbo and Xiamen. In the complex environment, it faces problems such as insufficient reliability of timing, difficult to set up unified management of multi-sites, and insufficient reliability and redundancy of backup. We broke through the bottleneck and realized dual-machine hot standby, multi-source timing, high-precision local timekeeping, and remote monitoring and networking technologies, becoming the representative of "Trusted Time Guarantee".