Abstract: Fuel flow regulators are core components of the main fuel systems in aero-engines; they supply engine with power. A fuel flow regulator was found to have unstable flow. This paper analyzed and calculated the effect of variable metering plunger sleeve assembly, the variable pressure(P_3P), fly weight, temperature compensation mechanism, edge of speed control sleeve metering on flow change. By product testing and engine equipment-testing, the cause of the failure of the fuel flow regulator was confirmed .By means of refining the variable metering plunger to improve the surface finish, adjusting the fly weight assembling clearance to improve the anti-contamination ability, controlling the form tolerance between the temperature compensation mechanism and some components of the speed control sleeve to improve the operational flexibility, and determining the clearing cycle for the transferred valve of the fuel flow regulator to improve the fuel flow stability, the flow stability of the fuel flow regulator can be improved.