Abstract: Uniaxial compression test was conducted on pre-cracked coal sample, and infrared radiation temperature and its change rule of the pre-cracked coal sample under loaded breaking were researched. The experimental results show that infrared radiation temperature curve will mutate in process of loaded breaking of the pre-cracked coal sample, and the infrared radiation temperatures of the pre-cracked coal samples with different angles will suddenly increase during main rupture. The mutation rate of infrared radiation temperature increases first and then decreases with increase of pre-cracked angle during main rupture, and the mutation rate of infrared radiation temperature of the pre-cracked coal sample with 45° is the largest. The change rule of infrared radiation of the pre-cracked coal sample is closely related to load and pre-crack, which can reflect internal rupture of macroscopic defective coal sample under load.