The invention discloses an environmental wind tunnel temperature control system, which includes a wind tunnel heat exchanger, a main pipe circuit and a plurality of heat exchange branches, the wind tunnel heat exchanger is installed in the expansion section of the wind tunnel, and the main pipe circuit is connected to the air tunnel The inlet and outlet pipelines of the heat exchanger, a plurality of heat exchange branches are connected in parallel to the main circuit and can circulate independently with the help of the main circuit. The heat exchange branch includes a refrigerant circulation unit and a heat exchange circulation unit. The brine circulation unit includes an outflow pipeline, a return pipeline, a drive pump, a three-way valve, and an adjustment branch. The outflow pipeline connects the main circuit and the heat exchange circulation unit, and three-way pipes are installed in sequence along the flow direction on the outflow pipeline. The valve and the driving pump, the return pipeline is connected to the main circuit and the heat exchange circulation unit downstream of the outflow pipeline, and the regulating branch is connected to the outflow pipeline and the return pipeline by means of the three-way valve. The invention adopts a three-way valve to change the mixing ratio according to the temperature feedback, the variable is unique, and the adjustment is simple.