Based on the Nagel-Schreckenberg models of traffic flow， a cellular automaton traffic model with different-maximum-speed vehicles mixed on single lane is proposed， which considers public transit and harbor-shaped bus stop. The influence of deceleration probability， the density of vehicles， the average stop time of public transit vehicles， the proportion of public transit vehicles occupied in the mixed vehicles and the bus stop spacing on mixed traffic flow are analyzed by computer simulation. The models traffic flow characters are presented and analyzed.