The invention discloses a piezoelectric liquid resistance energy harvester for a liquid-filled pipeline, and belongs to the technical field of vibration control. The piezoelectric liquid resistance energy harvester comprises an energy harvester main shell, an upper housing, a piston, a piston rod, a spring, additional mass blocks, a metal substrate group, piezoelectric ceramic composite plates, rubber pressing blocks, a first energy accumulator, a second energy accumulator, an energy storage and supply unit, a controller and a rectification plate, wherein the energy harvester main shell, the upper housing, the piston, the piston rod, the spring, the additional mass blocks, the metal substrate group, the piezoelectric ceramic composite plates and the rubber pressing blocks form a liquid-filled pipeline piezoelectric liquid resistance energy harvester main body; and the liquid-filled pipeline piezoelectric liquid resistance energy harvester main body is connected with the first energy accumulator, the second energy accumulator and the energy storage and supply unit. The structure of the piezoelectric liquid resistance energy harvester realizes that fluid and piezoelectrics are coupled to vibrate to transmit power to drive the energy harvester to increase resistance and reduce vibration, so that resistance increasing and vibration reducing effects on the pipeline are achieved, andvibration energy is converted into electric energy for storage; and the rectification plate is arranged in the pipeline, so that control over the rectification plate improves giant impact force on the pipeline due to bubble breakage in a flow conveying pipeline.