Abstract: Based on the fluid basic data such as flow rate, density, viscosity, surface tension, etc., according to the calculation model of two phase flow regime in SH/T 3035-2007 Guide for Pipeline Sizing in Petrochemical Industry, the VB6.0 was used as a platform to develop a user operation interface. The software was designed to judge the flow regime of Newton fluid pipe gas-liquid two phase flow and calculate pipe diameter. Proved by practical calculation, the software can not only develop the calculation efficiency by hand or by Excel, but also output the flow regime judgment results conveniently, which will bring convenience for the design effort.