The invention relates to a detector adaptable to the low-temperature environment and temperature control method thereof. The detector comprises a detector body; the detector body comprises a shell and a top cover; the shell is movably connected to the top cover at the rear end side; a main control board and a video capture unit which is connected to the main control board are arranged inside the shell; a heater is arranged at the backside of the main control board; the heater is connected to a direct-current power supply through a power supply circuit; the power supply circuit of the main control board is connected to a temperature control module which is equipped with a PID temperature controller; a temperature sensor is arranged at the main control board; and the temperature sensor is connected to the temperature control module which is equipped with the PID temperature controller. By means of the detector adaptable to the low-temperature environment and the temperature control method thereof, the heater is arranged on the backside of the main control board of the detector, thus the heater can be started to work when the temperature is below a set value, and heat the main control board to a set temperature, thus the normal work of the detector is guaranteed, and the technical problem that a prior detector cannot work normally under a low temperature is solved.