The invention relates to a booster pump for a live DC electric solar water heater, which comprises a DC motor live connection pipe, a battery connection port, a control switch, a mains connection port and a voltage stabilizing device, wherein, DC motor and the motor flange mechanical connection, the DC motor flange and the booster pump on the flange mechanical connection, the booster pump on the flange and the booster pump and live connection is a whole pipe, DC motor and motor cable interface and battery interface And the control switch wire is electrically connected, the control switch and the mains connection port and the voltage regulator device is electrically connected. So no electricity from the DC battery power booster pump movement, so that no solar water heaters hot water. Adopting the above scheme, the structure is simple and the installation is convenient.