The invention provides an extensible server container with a liquid cooling system, and relates to the field of servers, the extensible server container comprises an external shell, an internal cabinet and a cooling liquid distribution unit; the internal cabinet specifically comprises a plurality of cooling tanks used for placing server monomers, the bottoms of the plurality of cooling tanks are communicated and allow cooling liquid to enter, one side of each cooling tank is further provided with a hot liquid interlayer used for receiving heat-carrying liquid, and the plurality of cooling tanks share one hot liquid interlayer; the cooling liquid distribution unit specifically comprises a balance pipe, a liquid inlet pipe and a liquid discharge pipe, the liquid inlet pipe is communicated with the bottom of the cooling tank, the liquid discharge pipe is communicated with the bottom of the hot liquid interlayer, and the balance pipe is communicated with the upper part of the hot liquid interlayer, so that liquid higher than the upper liquid level in the hot liquid interlayer flows out of the hot liquid interlayer. The system is high in cooling efficiency, good in expandability, obvious in energy-saving advantage, uniform in cooling, free of local overheating and small in influence on the environment temperature.