In order to effectively improve the mechanical performance and damage resistance of prefabricated prefabricated box culverts for highways during construction and service periods, this paper proposes a new type of reinforced concrete structure prefabricated double toothed upper and lower assembly cover plate culvert for highways. Based on actual engineering parameters and material properties, finite element simulation software was used to simulate, and it was found that under different filling heights, the deformation of the top plate of the cover culvert was significant at a distance of 1.5 m from the leftmost center and 1.5 m from the side wall height center. The stress concentration phenomenon at the joint between the top plate teeth and the side wall was obvious. Based on the stress and deformation characteristics of the culvert body, different cross-sectional forms and connection methods of the cover box culvert body were designed and simulated for comparison. It was found that the trapezoidal side wall cross-sectional form with narrow upper and wide lower width and the 0.3 m wide plate tooth structure were more conducive to the stress of the side wall. Finally, a prefabricated double toothed slab culvert with trapezoidal side wall section, 0.1 m slab tooth width, and staggered slab construction method was selected. After optimization, the deformation and stress values are significantly reduced, meeting the requirements of bearing capacity. It has good compressive and shear mechanical properties and deformation resistance. Considering the economic and prefabrication rationality, it can provide reference for practical engineering of similar prefabricated box culverts.