The invention relates to an environment control unit for a dangerous cargo carrier vehicle, which comprises an environment detection and adjustment system, an early warning system, an emergency coolant system, wherein the environment detection and adjustment system detects the temperature, pressure and humidity data in a carriage by utilizing various sensors arranged in the carriage and adjusts by utilizing a small size air-conditioner arranged outside the carriage. The invention has the effect that the internal environmental parameter, temperature, humidity and pressure are adjusted and controlled to ensure that the dangerous cargo to be transported is in a safe environment.