A modular liquid-cooled server chassis, (100, 200, 300), wherein the chassis (100, 200, 300) comprises: a case 110, 210, 310); one or more liquid-cooled modules (120, 220, 320), wherein each liquid-cooled module (120, 220, 320) comprises a housing (121, 221, 321), a gas outlet valve (122, 222, 322) and a liquid return valve (1 23, 233, 333), wherein the gas outlet valve (122, 222, 322) and the liquid return valve (123, 233, 333) are opened when the liquid-cooled module (122, 222, 322) is in operation, and the liquid-cooled module (120, 220, 320) is inserted with a single server during operation and is filled with coolant; a connector (130, 230, 330) for connecting the liquid-cooled module (120, 220, 320) to an external power source; and a circulation section comprising a gas outlet pipe (141, 241, 341) a liquid return pipe (142, 242, 342), a steam treatment zone (143, 243, 343), and a liquid collection zone (144, 244, 344), wherein, the gas outlet pipe (141, 241, 341) is connected to the gas outlet valve (122, 222, 322) and is used to transport gas from the liquid-cooled module (120, 220, 320) to the steam treatment zone (143, 243, 343); the liquid return pipe (142, 242, 342) is connected to the liquid return valve (123, 223, 323) and is used to transport liquid from the liquid collection zone (144, 244, 344) to the liquid-cooled module (120, 220, 320); the steam treatment zone (143, 243, 343) is provided with a condenser (1431, 2431, 3431) for cooling the gas in the steam treatment zone (143, 243, 343); and the liquid collection zone (144, 244, 344) is used for collecting liquid from the steam treatment zone (143, 243, 343). a case 110, 210, 310); one or more liquid-cooled modules (120, 220, 320), wherein each liquid-cooled module (120, 220, 320) comprises a housing (121, 221, 321), a gas outlet valve (122, 222, 322) and a liquid return valve (1 23, 233, 333), wherein the gas outlet valve (122, 222, 322) and the liquid return valve (123, 233, 333) are opened when the liquid-cooled module (122, 222, 322) is in operation, and the liquid-cooled module (120, 220, 320) is inserted with a single server during operation and is filled with coolant; a connector (130, 230, 330) for connecting the liquid-cooled module (120, 220, 320) to an external power source; and a circulation section comprising a gas outlet pipe (141, 241, 341) a liquid return pipe (142, 242, 342), a steam treatment zone (143, 243, 343), and a liquid collection zone (144, 244, 344), wherein, the gas outlet pipe (141, 241, 341) is connected to the gas outlet valve (122, 222, 322) and is used to transport gas from the liquid-cooled module (120, 220, 320) to the steam treatment zone (143, 243, 343); the liquid return pipe (142, 242, 342) is connected to the liquid return valve (123, 223, 323) and is used to transport liquid from the liquid collection zone (144, 244, 344) to the liquid-cooled module (120, 220, 320); the steam treatment zone (143, 243, 343) is provided with a condenser (1431, 2431, 3431) for cooling the gas in the steam treatment zone (143, 243, 343); and the liquid collection zone (144, 244, 344) is used for collecting liquid from the steam treatment zone (143, 243, 343).