The problems of uneven flow field and low drying efficiency in the negative pressure electric heating dryer were found and supposed to solve in this study. Based on Fluent, numerical simulation of wind velocity field and temperature field in negative pressure electric heating dryer was carried out. And by using the improved design of SolidWorks internal structure of the dryer, the main factors influencing the drying efficiency of the working parameter and structure parameter were tested. By using changing the working parameters and optimize the structure, the internal flow field uniformity of the optimal effect of dryer were achieved. The results showed that the SolidWorks optimization design of dryer internal flow field uniformity was obviously improved compared with the original structure, and the optimized structure parameters could meet the design requirements. Therefore, this method greatly improved the work efficiency of heat utilization of dryer.