Abstract: Taking the tail lamp of agricultural tractor as the research object, it analyzes the internal structure and technology of the tail lamp, designs and analyzes the mold forming scheme and design process according to the particularity of the two-color mold, and completes the design of the two-color plastic part mold of the tail lamp based on Auto CAD and CAE software. The mold opening test shows that the product meets the design requirements, the whole product structure is stable, and the transparency is also very good, indicating that the mold structure designed in this paper is reasonable, the process flow is reliable, which can meet the actual production application, and the engineering application value is high.