Taking the automobile headlamp leveler transmission system as study object,based on the mechanical dynamic simulation technology,the dynamic characteristic of leveler transmission systems is studied.The dynamics simulation model of multistage transmission system of leveler is established in ADAMS. The influence of each transmission friction on shaft thrust force is obtained. The test result shows that simulation model can forecast the influence of each transmission friction on shaft output force,the reliability of the model is verified. It can provide as reference for the leveler design and process optimization.