Abstract: Objective: In view of the current situation of unbalanced passenger flow and high operation cost of urban rail transit, a scheme of urban rail transit train flexible formation and operation is proposed. Method: Based on the investigation and analysis of urban rail transit current situation, the schemes and shortcomings of the existing vehicle configuration and traffic volume expansion are analyzed, and corresponding solutions are put forward. Flexible formation is an effective way to deal with the current situation, meaning to adopt largeformation highfrequency in peak hours and smallformation highfrequency in normal hours, and smallformation for low passenger volume lines. According to the demands of passenger flow in different hours, large and small formation are mixed. Flexible formation vehicles are recommended to use 2car or 3car as the basic formation and to choose 2+2 or 3+3 doubleheadings. Flexible formation is divided in two types: formation in depot and formation at main line station. Flexible formation is implemented through two types of coupling: the rear vehicle colliding with the front vehicle at a speed of less than 3 km/h to couple, and the rear vehicle stopping at a distance of 300 mm from the front vehicle to couple through telescopic couplers. Result & Conclusion: It is found that there are still some problems to be solved for realizing urban rail transit vehicle flexible formation, for example, the precise telescopic coupling design of telescopic couplers can meet the requirements that after the vehicles are parked at an interval distance of 300 mm, the two head couplers can automatically extend 150 mm respectively to complete the coupling; how can signaling system control the vehicle accurately without accidental collision.