Nonstable fuel flow measurelnent is a insoluble difficult pro-blem for inside and outside our country. It is a very important reason that there is no reliable nonstable fuel flow calibrating apparatus,and so there is no method to know about its dynamic characterlstic. This paper introdu-ces the basic theory and pract ising project about nonstable fuel f1ow calib-rating apparatus,for example turbo fuel-flow meter of an airbone enginefuel system.