Belonging to the field of evaporation concentration, the invention relates to a closed type solution circulation zero discharge evaporation concentration system and a method thereof. The system comprises a solution pump, a dehumidifier, a condenser, a humidifier, a circulating pump, an evaporative crystallizer, a stirring kettle, a centrifuge, a throttling valve, a blower, a compressor, and an induced draught fan, etc. The system utilizes the characteristic that air at different temperatures has different moisture-carrying capacities, through humidification and dehumidification of air, evaporation concentration under atmospheric pressure and low temperature can be realized. Low-boiling point working medium circulation is employed to realize heat transfer from low temperature to high temperature, an external heat source is unnecessary for heating of the solution, and cooling crystallization of a concentrated solution can be realized without an external cold source, continuous work of the system can be ensured only by providing a small amount of electrical energy, and the energy-saving effect is remarkable. At the same time, the solution in the system is closed circulation, the salt content of the solution is reduced by cooling crystallization so as to realize zero discharge of the solution, and the system has obvious environmental protection advantages.