Abstract: This article researches the hydrokinetics mechanism of the pneumatic agitator of the FJCA20 flotation machine by PIV test and FLUENT simulation.It reveals the internal flow field distribution of the pneumatic agitator fully.Due to the measured test velocity and the simulate calculted velocity is anastomosis at the major monitor points,so the FLUENT simulation can replace PIV test as a easy and reliable research method,which can establish a theoretical foundation for the optimization and enlargement of fluid equipments.