A method for increasing accuracy of measurement of body temperature includes a step of collecting an infrared signal to obtain an infrared signal value (step 1), a step of collecting a skin image to obtain a calibrating emissivity (step 2), a step of obtaining a calibrated infrared signal value according to the calibrating emissivity and the infrared signal value obtained in step 1 (step 3), and a step of making a conversion into an actual body temperature (step 4). Accordingly, an actual temperature value of the skin surface can be attained to increase the accuracy of measurement effectively, thereby allowing the measured result to be more close to the real body temperature of a tested target.
