用定压法测量扩散泵的抽气速率是目前各国从事扩散泵研究和生户的工作者所接受和使用的一种方法，而其在测量时所引起的种种误差已做了许多研究和探讨（１）。但本文则对在不同温度下所进行的抽气速率测量和滴管内由于油柱上升而引起的计算误差加以分析最后推荐较合理的，简便的扩散泵用定压法测量抽气速率的计算公式。 Constant pressure method to measure the diffusion rate of the diffusion pump is diffusion diffusion pump countries in the study and use of workers accepted and used by a method, and its measurements caused by a variety of errors have done a lot of research and discussion (1). However, this paper analyzes the calculation of the pumping rate at different temperatures and the calculation error caused by the rising of the oil column in the dropper. Finally, a more reasonable and convenient diffusion pump is used to calculate the pumping rate by the constant pressure method .