Abstract: Technical and economic comparison and selection must be done during the process calculation of boosting transmission for long-distance gas pipeline, which is a time-consuming system engineering due to the numerous and interplayed parameters involved in its analysis and calculation process. The method on the initial pipe diameter chosen by gas flowrate can be used to expand other process calculations, for instance, the calculation in pressure ratio comparison/selection and station spacing for different pipe diameters between two intermediate compressor stations, shaft power of compressor and outlet gas temperature of compressor, etc.. At the same time, a simplified formula for shaft power calculation of centrifugal compressor is proposed, and the formula for outlet gas temperature of compressor is amended.Engineering practice has proved that the calculation method mentioned above is simple for application, and the calculation result has sound accuracy.