The suppression level of internal stray radiation of atmospheric corrector in short-wave is a key indicator for its optical design and performance evaluation, especially for infrared optical systems, in which the internal stray radiation cannot be ignored. In order to measure the output of the stray radiation inside the instrument, a method based on radiation calibration is proposed. First, we obtain the linear relationship between the input and output of the instrument by controlling variables, and the model of the radiation calibration is established. Then, the background signal of the instrument at different ambient temperatures is measured, and a maximum deviation of 4.45% is found compared to theoretical values, which verifies that the calibration model is valid. The proposed method can be used to calculate the internal stray radiation correction of atmospheric corrector at different ambient temperatures and gain values, which simplifies experimental processes and evaluates the stray radiation index of the atmospheric corrector.