Abstract: The analysis of the annual temperature distribution of bridge is the basis of studying the temperature stress of concrete box girder. This study took a concrete continuous box girder in operation period in Qiqihar as the research object, and carried out a 1-year monitoring of the temperature. Data collected from the monitoring process were then analyzed by statistical means. The temperature variation law of different positions at the middle section of the 11 span was obtained, and the probability density distribution model was established using the weighted Weibull distribution. The results showed that the annual temperature change trend and the annual temperature difference change trend had obvious seasonal variation and geometric symmetry; meanwhile, there was a certain horizontal temperature difference between the roof and the floor, and a vertical temperature difference between the roof and the floor. Through the weighted sum of two Weibull distributions, the positive and negative temperature difference of concrete box girder in the cold region was fitted, and the parameters of probability density distribution function of temperature difference between different measuring points were obtained.