The invention relates to a power supply system management circuit used for gravity measurement, which comprises an AC input conversion module, a DC input conversion module, a battery module, a charging control module, a discharging control module, a switching control module and an output conversion module, wherein the charging control module selects one path, with higher voltage, of the AC input conversion module and the DC input conversion module as a charging power supply for charging the battery unit; when a voltage of the battery unit is higher than or equal to a threshold voltage, the voltage of the battery unit is output to the switching control module; and the switching control module selects one path, with the highest voltage, of the AC input conversion module, the DC input conversion module and the discharging control module as a charging power supply, and transmits the charging power supply to the output conversion module. The uninterruptible power supply circuit is provided with three power supply modules including alternating current, direct current and battery, adapts to the demands of various occasions, uses the alternating current and the direct current for charging the battery unit, and ensures the charging of the battery under different occasions.