The invention discloses a cellphone-APP-based remote control system of vehicular conditioners and a control method thereof and relates to the field of vehicular service systems. The cellphone-APP-based remote control system of vehicular conditioners comprises a KSS keyless start system in real-time connection with a vehicular T-BOX through a CAN (controller area network) bus, a remote automatic parking system, an interior environment monitoring device, a remote door/window locking system, a TSP (telematics service provider) cloud service platform, and the vehicular T-BOX; the vehicular T-Box is in real-time connection with a user mobile APP through a 3G communication network. The cellphone APP is connected with the vehicular T-BOX, the vehicular T-BOX receives, in real time, the interior temperature and humidity data information received, and transmitting a control command to a conditioner ECU (electronic control unit), the conditioner ECU controls a conditioner system to run accordingto temperature and humidity information set on the user cellphone APP, the functions of automatically shutting down the conditioner system when set conditions are met, automatically parking a vehicleafter engine start and automatically locking doors and windows are provided, control safety, convenience and stability are improved for the remote control system, the remote control system has high intelligence level, good health of use, low energy consumption and good environmental friendliness.