In view of the problems of poor distribution control ability,difficulty in monitoring the distribution process,and large consumption of transportation resources of mixed-flow large-scale assembly workshop,a material delivery method was proposed for digital twin workshop based on genetic algorithm.A multi-objective model of digital twin workshop material distribution was established based on the real-time interaction between physical distribution and twin distribution,genetic algorithm was used to generate the initial material distribution plan according to the bill of material,the initial distribution plan was simulated and optimized in the twin workshop,and the digital twin model was used to monitor the distribution situation of equipment and to solve the unexpected situations in the distribution process in time.Finally,taking the material distribution of a diesel engine assembly workshop as an example,it is proved that the genetic algorithm combined with the digital twin assembly workshop material distribution scheme can reasonably arrange material transportation,the crane transportation time is reduced,the safety of AGV work is improved,and the performance of workshop distribution system is optimized.