Abstract: In order to reconstruct multiple compound traffic accidents and determine their causes,a method of retrograde stepwise reconstruction was developed.Firstly,a small amount of accident information collected was analyzed and identified,according to the results and a complex accident was divided into several collision sequences.Then,the collision process of the back-end timing was simulated and the time-series vehicle motion state was obtained,the consistency of the reproduction process was determined by using the consistency constraint scheme,if consistent,the previous collision sequence will be simulated in the same way,and this step will be pushed backward continuously until the accident simulation was completed.The process and causes of the accident were determined.Finally,the method was verified by reconstructing a double-sequence compound accident.The results show that this method can be used to reconstruct the double-sequence compound accident accurately,and make the error rate smaller,and that collection and evaluation analysis of information on the earlier stage of an accident are beneficial to determining the formation of the accident.

Key words: traces identification, retrograde stepwise, PC-Crash, accident reconstruction, compound accident