Abstract: In the construction of modern information platform, the time-frequency system provides a unified time-frequency reference for the platform, and its time keeping performance is the key factor for the efficient linkage and stable work of all components of the platform. Through the analysis and research of frequency reference source optimization and multi-clock integrated time-frequency processing technology, a high-precision time-frequency synthesis and time keeping method is proposed, and a high-precision time-frequency synthesis and time keeping system is designed, through selecting rubidium atomic clock as frequency reference source, atomic time synthesis and control based on multiple rubidium atomic clocks, and real-time cross-comparison of similar sources to select the optimal master clock and the backup master clock, to improve the system's time keeping performance. The feasibility and effectiveness of this method are verified by comparison experiments with the traditional method.