Abstract: By using the bus GPS data and map matching algorithm, this paper depicts the actual bus running status, counts the one-way time consumption and arrival time interval of the bus, quantitatively analyzes the reliability of bus travel time, evaluates the running effect of bus lines, and puts forward a method of identifying road sections with high traffic congestion based on an increasing rate of travel time. With the bus track data in Harbin as an example, this paper analyzes the operation of a bus No.84. The results show that the one-way punctuality of this line is 88.33%, and the one-way punctuality stability is 61.55%. The congestion model based on an increasing rate of travel time can effectively identify frequently congested sections of the line, and spatial distribution of the congested sections can be seen on the heat map. Through the analysis of the track data, changing characteristics of the bus operation are discovered, which provides an important reference for solving urban traffic congestion and improving bus service level and reliability.