Roundabout is mostly located in the downtown area, which can beautify the urban landscape and alle- viate traffic. However, there is a widespread traffic jam in the ring intersection, which brings heavy traffic capac- ity in the central area of the city, and a large number of traffic flows lead to serious human and car conflicts, re- sulting in great hidden danger to the traffic safety of the roundabout. By analyzing the traffic characteristics of pedestrian crossing in road crosswalk, this paper constructs a multi-objective optimization model of signal control and selects genetic algorithm. It shows that the model can effectively improve the traffic capacity of the round- about and alleviate traffic conflicts in China.