A mathematic model for the pumping performance of a diaphragm vacuum pump (DVP) is constructed
in the paper，and the finite element analysis method is used to calculate the change of the working volume，which is a parameter in the mathematic model． Then，by using the proposed model and by means of the finite element simulation，the pumping performance of a DVP is calculated． Finally，the prediction results of the working volume and the pumping performance are compared with the experimental ones． The comparison demonstrates that the proposed methods of calculating the working volume and the pumping performance are effective，and the result precision can meet the engineering requirements． In addition，the proposed methods can precisely predict the pumping performance of products and optimize the design during the process of design and development，which helps to improve the pumping performance and shorten the development cycle．