The invention discloses a machine room air conditioner synchronizing supercooling and superheating. The machine room air conditioner comprises a compressor, a condenser assembly, an expansion valve and an evaporator assembly which are all in sequential connection, wherein an outlet of the evaporator assembly is connected with an inlet of the compressor to form a refrigeration circulation loop. The condenser assembly comprises multiple branch condensing coils, a high-pressure liquid storage tank, a liquid collection device, a supercooling coil and a condenser fan, wherein the supercooling coil is arranged in a position with the best heat exchange effect in the condensing assembly and is parallel with the multi-branch condensing coil, an outlet of a branch condensing coil with the worst condensing effect in the multiple branch condensing coils is connected with an inlet of the high-pressure liquid storage tank, an outlet of the high-pressure liquid storage tank and outlets of other branch condensing coils are together connected with an inlet of the liquid collection device, and an outlet of the liquid collection device is connected with an inlet of the expansion valve though the supercooling coil. The machine room air conditioner effectively resolves the problems of loss of the obtained degree of the supercooling, avoids wet compression of the compressor, and can improve refrigeration performance and working stability of the machine room air conditioner.