By analyzing the structure of three-tank liquid level control system and the corresponding mathematical model, establishes the system simulation model based on the simulink of MATLAB. Tunes the parameters PID and proposes the combined method of segmented variable parameters PID and adaptive fuzzy PID for the control of system. Finally, builds the control platform and designs control program with the virtual instruments to realize the control process monitoring and dynamic simulation. The simulating result verifies the devised control strategy correct and effective.