The invention discloses a rail traffic vehicle depot roulette and vehicle washing line combined arrangement structure. The rail traffic vehicle depot roulette and vehicle washing line combined arrangement structure comprises a vehicle depot applying storeroom, a roulette vehicle washing storeroom, a depot inlet line, a depot outlet line, a first lead track, a second lead track, a vehicle washing line and a roulette; a first forked road is formed between one end of the first lead track and the depot inlet line; a second forked road is formed between one end of the vehicle washing line and the first lead track; a third forked road is formed between one end of the roulette and the first lead track; the vehicle washing line and the roulette penetrate through the roulette vehicle washing storeroom correspondingly; and the roulette is connected with the depot inlet line through a single crossover. According to the rail traffic vehicle depot roulette and vehicle washing line combined arrangement structure, a roulette storeroom and the vehicle washing storeroom are combined-arranged to form the roulette vehicle washing storeroom, the roulette vehicle washing storeroom has the functions ofroller spinning and vehicle washing, the width of a vehicle depot storeroom is saved, meanwhile site area of the vehicle depot can be saved, the functions of a certain effective length and vehicle washing in-out storeroom are achieved, the construction cost is reduced, and feasibility of the scheme is guaranteed.