The invention discloses a time service method and device for a power grid terminal. The method comprises the following steps: acquiring a broadcast timing signal, wherein the broadcast timing signal comprises a time code; decoding the time code to determine time information corresponding to the time code; and updating the current time of the power grid terminal according to the time information. The method disclosed by the invention is wide in applicable geographic range and free from network connection, namely, the time correction can be executed when the power grid terminal is not communicated with a main station of a power information acquisition system; and meanwhile, the time service precision of the method is high, the 24-hour automatic correction can be realized, and an accumulated error in RTC circuit time correction is inexistent.