The numerical simulation of a three-paddle planetary agitator used for mixing high-viscosity paste was carried out and the propeller type was studied.The other two schemes were obtained by changing the pitch of the propeller.The flow field distribution, velocity distribution, torque and power of the three schemes were compared by simulation analysis.The results show that when the pitch is increased and the paddle type is closer to the frame type,the discharge and tangential circulation ability of the agitator is enhanced, the axial circulation ability is weakened, and the stirring torque and power are increased.When the pitch is reduced and the paddle type is closer to the belt type,the axial circulation ability of the agitator is enhanced,the discharge and tangential circulation ability is weakened,and the stirring torque and power are decreased.Suitable pitch and paddle type are helpful to improve the compound stirring effect of planetary stirrer.