In modern scientific research,the equations of complex models often appear in the form of partial differential equations At this time,the model can be solved by using the online solution method,and the partial differential equations can be converted into ordinary differential equations and then solved Different approximation formats of online solution method will also have different results and errors,so exploring the optimal approximation format is an important step in scientific research to avoid errors Based on the Burgers equation,this paper discusses the optimal approximate format of online solution method with MATLAB tool,and the analysis and verification are combined with the actual model in the chemical process application The results show that there is an optimal approximate format for the online solution method By applying this format,the chemical process model can be solved quickly and accurately,and an ideal model curve can be obtained.