Vehicle-mounted constant temperature control system and temperature control method

The embodiment of the invention discloses a vehicle-mounted constant temperature control system and a temperature control method, and belongs to the technical field of automotive electronics. The vehicle-mounted constant-temperature control system comprises a compressor, a condenser, a first evaporator, a second evaporator, a heat exchange pipeline, a constant-temperature pipeline and a constant-temperature box. Wherein an outlet of the compressor is connected with an inlet of the condenser, a first outlet of the condenser is connected with an inlet of the first evaporator, an outlet of the first evaporator is connected with an inlet of the compressor, and the first evaporator is used for providing cold air for the indoor space of the vehicle. A second outlet of the condenser is connected with an inlet of the second evaporator, an outlet of the second evaporator is connected with an inlet of the compressor, the second evaporator makes contact with the heat exchange pipeline, the two ends of the heat exchange