Presolving techniques in linear programming model

Proper presolving of the linear programming model can save the solve time of large-scale linear programming and increase the accuracy of the solution. The paper presents more comprehensive techniques on the presolving of linear programming,and some practical presolving techniques are also introduced. A computer procedure was written to demonstrate the impact of some standard models. The results are presented to elucidate that these techniques can simplify the models consumedly and practicably.