Aiming at the assembly confliction problem of the small-batch multi-variety assembly,a service-oriented collaborative assembly method was proposed.The assembly tasks were classified into two types:common tasks and specific tasks which were all completed by the robots which could offer common service or specific service relatively.The service tag was proposed to realize the collaborative communication between robots and products to avoid the confliction between multi-robots and multi-products.To verify the effectiveness of the proposed method,the CPN assembly model was applied to analyze the collaborative assembly method,and the modified quantum inspired genetic algorithm(MQGA) was also proposed to optimize the distribution of service tags,which could improve the assembly efficiency.Lastly,the method was applied in the assembly of two kinds of products.The experiment results show that the proposed method can be used to solve the confliction problems between multi-robots and multi-products in small-batch multi-variety assembly.With the optimization of the MQGA,the assembly time is reduced.It is concluded that the service-oriented collaborative assembly method can be applied in small-batch multi-variety assembly effectively.