In view of a research on the oscillation of control variables brought about by the viscous characteristics of valves, a binary tree viscous model has thus been established based on the valve motion characteristics. By introducing Smith predictor into the Knocker compensator algorithm to offset the hysteresis effect of feedback, a multi-threshold Knocker compensation control strategy is established optimized by the bottle sheath swarm algorithm. Based on an extensive comparison experiments, the results show that the improved Knocker compensation strategy is characterized with a better effect on the reduction of the control valve oscillation than the single-threshold Knocker strategy. IAE and ISE indexes of the former are reduced by 73.7% and 80.7% respectively compared with the latter, thus keeping the steady-state error of the control below 1%, with the action times of the valve stem greatly reduced as well.