This paper aims to study the problem of excessive cost caused by the single material distribution mode in the production process in consideration of optimal cost. To minimize the total cost of material distribution

an improved material distribution combinatorial optimization model based on batch distribution and kit distribution modes was proposed. The model was then applied to a case study of the assembly line of automobile production workshop to provide the optimal design of material distribution and verify the effectiveness of the model. Experimental results show that compared with the batch distribution and kit distribution modes

the improved combinatorial optimization model could reduce the cost by 83.6% and 70.8% respectively

and meanwhile exhibited better robustness. The kit distribution mode was more likely to be chosen for delivering the materials loaded in pallets than materials loaded in cartons. Under full constraint conditions

the kit distribution mode was more likely to be adopted. The priority of influencing factors of distribution mode choice was: total stacking area at the edge of production line

rated loading capacity of tractor

and rated loading capacity of forklift. The results of this paper can provide suggestions for workshop management.