Establish the mathematical model for distillation columns running system, and calculate configurable and performance parameter. Using MATLAB to simulate and analyze dynamic external load such as wind load and earthquake load, do the curve fitting. That provides theoretic results and simulating curve for designing and modifying column structure. New dynamic continuous computation in external load is substituted for the traditional subsection computation for the first time. Numerical superposition and curve fitting of load along the entire tower is completed. That avoids discontinuous stress in the junction point generated by subsection computer with deviation value to the full. Bending moment calculated can infinitely close to the ground beyond section numbers, and describes the external load more truly and reliably. Simulation results of an actual system demonstrate that precision of continuous computation is obviously higher than that of subsection computation. Simulation software based on MATLAB has high efficiency, good stability, which is convenient to checkout columns strength, rigidity and stability under dynamic external load.