In order to improve the temperature measurement accuracy of space cameras,the tolerance analysis is applied to temperature measurement circuits.The principle of a temperature measurement circuit is studied and a variety of influencing factors of temperature measurement accuracy are discussed.Several kinds of tolerance analysis methods are described, and their respective advantages and disadvantages are compared.Then the worst-case analysis method is chosen to analyze the tolerance of the temperature measurement circuit.Finally, a novel method for improving temperature measurement accuracy is proposed according to the analysis results.After validating proposed method,it is shown that the measurement accuracy of the improved temperature measurement circuit is ±0.3℃, 30 times higher than that of the original method,which can meet the requirements of temperature measurement in -14 ℃-+50 ℃.