Objective By analyzing the working conditions of the conveyor, the factors affecting the transportation were studied and the mechanical characteristics model of the conveyor was determined. Methods Analytical mechanics method was used to obtain the mechanical characteristics model affecting the equal-pitch variable pitch factor. The three-dimensional model was built using Unigraphics NX and imported into Ansys workbench software. The static simulation, modal analysis and optimization design were performed. Results Through simulation analysis and optimization, the maximum deformation of the cream conveyor occurred at the top edge of the screw shaft, and the mass, total deformation and equivalent stress of the optimized structure were reduced by more than 10%. Conclusion This method could provide a theoretical reference for mechanical research and structural design of conveyors.