A temperature-strain integrated measuring method in high-temperature tension test comprises the following steps: 1) establishing a relation between gray scale and temperature; 2) in the calibration stage: (1) heating material to be detected, collecting temperature change data of points to be measured by a two-color thermometer, and collecting image data simultaneously by an industrial camera; (2) converting the image data into a grey-scale map in a computer and extracting the grey level of the tested points; (3) fitting a formula according to the gray level data and the temperature data; and (4) determining parameters A and B; and 3) in the measuring stage: (1) extracting initial coordinates and initial grayscale characteristics of two mark points in an initial grey-scale map; and (2) converting the grey-scale map into a temperature map according to the relation between gray scale and temperature and the parameters A and B obtained in the calibration stage, so that full-field temperature can be obtained in real time. Meanwhile, by utilizing the initial grayscale characteristics of the two mark points and through an initial scale distance L and a follow-up scale distance L', scale distance change delta L can be obtained, thereby obtaining axial strain delta L/L. Through the utilization of the two-color thermometer and the high-resolution industrial camera, both high-precision full-field high temperature measurement and high-precision strain measurement are realized.