The invention discloses a method, system, and apparatus for preventing restarting of an infrared camera. The method comprises: a power supply voltage of an infrared camera is detected; whether the power supply voltage is larger than a lower limit value of a stable value zone is determined; if the power supply voltage is larger than the lower limit value of the stable value zone, an equivalent voltage of pulse width modulation is adjusted according to a first preset rule until the brightness of an infrared lamp included by an infrared lamp panel reaches a maximum value, wherein the equivalent voltage is used for controlling the brightness of the infrared lamp; and if the power supply voltage is smaller than or equal to the lower limit value of the stable value zone, the equivalent voltage of pulse width modulation is adjusted according to a second preset rule, so that the brightness of the infrared lamp included by the infrared lamp panel is reduced. Therefore, a problem of how to prevent restarting of an infrared camera effectively in the prior art can be solved.