The invention provides a liquid heat dissipation system. The system includes a first heat dissipation module, the first heat dissipation module is provided with a first inlet, a first outlet, and a first module liquid accommodating space for working liquid to circulate, the first inlet and the first outlet are communicated with the first module liquid accommodating space, and the working liquid flows into the first module liquid accommodating space through the first inlet; the system further comprises a second heat dissipating module, the second heat dissipation module is provided with a second inlet, a second outlet and a second module liquid accommodating space for the working liquid to circulate, the second inlet and the second outlet are communicated with the second module liquid accommodating space, and the working liquid flows into the second module liquid accommodating space through the second inlet; the first outlet is connected with the second inlet in a butt joint mode, the first inlet is connected to a heat exchange module, the second outlet is connected to a pump, and the heat exchange module is connected to the pump.