The calculation of rubber dam bag is low in efficiency and limited in precision. For the limitation and shortage,this paper puts forward the calculation method of the rubber dam bag based on numerical integration,and uses two numerical integration methods to solve the first and second types of elliptic integral and apply them to the calculation of rubber dam bag. The two methods have achieved high precision. The program compiled by the algorithm can calculate the parameters and coordinates of dam bags accurately and quickly,and automatic drawing of rubber dam bag curve is realized by AutoCAD Automation technology. The research provides effective technical support for the technical research and comparison of rubber dam.