This study was aimed at analyzing the optimization of departure timetables for certain city bus routes. This was done by selecting two intersecting city bus routes that simultaneously serve as transit routes to solve the problem of passenger flow clog up, and building a city bus timetable optimization model that takes total waiting time, transfer waiting time and minimum non-transit waiting time as objective functions. Two city bus routes in Hohhot City, namely Line 4’s "JINYU Global Center ~ Affiliated Hospital of Medical University" section and Line 78’s "Hohhot Bus ~ Saihan District Education Bureau" section, were studied, and the optimization model was solved using genetic algorithm. The results show that the proposed city bus timetable optimization scheme can shorten the transit waiting time and total waiting time by 18.1% and 10.7% respectively, thereby validating the proposed optimization model’s effectiveness in improving the operating efficiency of intersecting routes.