The invention discloses a fully-closed intelligent electric control cabinet cooling system, which comprises a compressor, a condensation heat recovery adjustment valve, a heat recovery coil, an electric valve, a condensation coil, a condensation fan, a dry filter, a throttle valve, an evaporation coil, a baffle board, an electric heater, a circulating fan and a case. The cooling capacity for cooling each electronic and electric module inside the electric control cabinet is from the refrigerating capacity generated by a vapor compression refrigeration system at the evaporation coil, a constant dew point temperature mode enables the temperature and the humidity of the circulating cooling air to be controlled precisely, and due to the condensation heat recovery design, the cooling system is energy-saving and environmental friendly. The defects that the cooling mode of the cooling fan is largely influenced by interference of the surrounding air environment, and only insufficient cooling effects can be provided can be overcome.