The invention relates to a multistage-compressor mixed-flow energy-saving low-temperature multi-effect large-sized seawater desalination device, which consists of horizontal falling-film evaporators, a TVC (Thermal Vapor Compressor), spiral spoilers, an auxiliary heat exchange network, a computer control system, a fluid delivery pipe, and a control pump and a sensor on the pipe. The horizontal falling-film evaporators are sequentially connected. The spiral spoiler and a temperature and pressure acquisition device are connected before each horizontal falling-film evaporator. Each horizontal falling-film evaporator is additionally provided with an evaporator suction port control valve which is connected with the TVC through a gas gathering pipe, a flow speed control valve and a TVC suction port control valve. Compared with the prior art, the multistage-compressor mixed-flow energy-saving low-temperature multi-effect large-sized seawater desalination device provided by the invention has the advantages that the design is reasonable, the device is economical and practical, the problem of non-condensable gas is gathered among multi-effect evaporators is optimally solved and the problem of how to reasonably utilizing secondary steam is also optimally solved; the overall heat exchange efficiency of the multi-effect evaporators is improved, the water making ratio is improved and the cost of desalinated product water is reduced; the energy is saved, the structure is safe and reliable, the device is suitable for operation under multiple working conditions and the device is very convenient to operate and maintain.