The invention relates to a miniature hydrodynamic piezoelectric switch valve which comprises a piezoelectric oscillator, a 
liquid storage cavity, a driving hole, a flexible valve plug, a 
valve opening, an inlet, an outlet, a flow passage and driving liquid, wherein the piezoelectric oscillator is arranged at the upper part or the lower part of the 
liquid storage cavity; the driving hole connected with the 
liquid storage cavity is formed in the upper part, the lower part or the 
cavity wall of the liquid storage cavity; the flexible valve plug is arranged on the driving hole and matched with the 
valve opening; the piezoelectric oscillator, the liquid storage cavity and the flexible valve plug together form a sealed space filled with the driving liquid. The switch valve provided by the invention controls the opening and closing of a valve indirectly by virtue of hydraulic power, can fully utilize the overall deformation of a piezoelectric 
chip, and has the advantages of high response speed, good 
cut-off property, high 
cut-off pressure, 
low leakage rate and easiness in 
processing and manufacturing. The piezoelectric driving part and the 
fluid control part of the switch valve can be separated through a liquid 
guide tube, and the mounting form is flexible.