The invention discloses a body temperature measuring method and device. According to the method, an actual temperature rise curve detected by a temperature probe is regarded as a result of fitting a first ideal temperature rise curve and a second ideal temperature rise curve. By means of the four equitime interval points on the actual temperature rise curve and actual temperature corresponding to each equitime interval point, first ideal temperature, corresponding to each equitime interval point, on the first ideal temperature rise curve and second ideal temperature, corresponding to each equitime interval point, on the second ideal temperature rise curve are calculated; then, the body temperature is predicted on the basis of the first ideal temperature rise curve or the second ideal temperature rise curve to obtain the body temperature. Compared with the prior art, the method adopts the ideal temperature rise curves for predicting the human body temperature, meets the requirement of a Newton heat conduction formula, and improves the prediction accuracy.