The public transport space is a high-risk environment for the spread of the epidemic because of the dense flow of people and the narrow and closed internal space of the vehicles． The characteristics of customized bus “one person，one seat”and “one stop direct”are just in line with the requirements of epidemic prevention and control． Therefore，considering the advantages of conventional bus and customized bus，this paper proposed a collaborative optimization method of urban conventional bus and customized bus under epidemic prevention and control． It established a total cost minimization model considering risk cost，operation cost and travel cost，and designed an improved column generation algorithm to solve the model． The results show that: the collaborative optimization scheme proposed in this paper is significantly better than the independent conventional bus scheme and customized bus scheme，and ensures the service level of passengers; with the decrease of risk level，the number of conventional bus lines increases，the number of customized bus lines decreases，and the total number of service increases with the decrease of epidemic level． The study confirms the beneficial effect of customized bus on epidemic prevention and control and provides a theoretical guidance for the optimization of public transport system under the situation prevention and control．