The satellite time service technology is limited by the measurement accuracy of the classical radio signal, and the time service accuracy can only reach the ns level. In this paper, a satellite time service scheme based on microwave-optical wave-entangled signals is proposed. The advantages of long-distance transmission of microwave signals and single-photon detection of optical wave signals are effectively combined using a cavity electro-opto-mechanical converter. The phase difference is calculated using a phase-conjugating processor to obtain accurate time-difference information. Through theoretical analysis and simulations, it is demonstrated that even if the quantum signal is in low entanglement, the proposed scheme can improve the satellite time service accuracy to the ps level.