The invention discloses a piezoelectric sensor calibrating method. The method comprises the following steps of: putting a piezoelectric sensor to be calibrated into a cylinder; inflating air into the cylinder through an aerostatic press, wherein the pressure value of inflated air is displayed synchronously by a pressure meter, and water in the cylinder generates a dynamic water pressure under the action of the dynamic air pressure; according to the dynamic water pressure, outputting a voltage value by the piezoelectric sensor in the cylinder and displaying the fluctuation and change of the voltage data in real time by an oscilloscope; according to the voltage data displayed by the oscilloscope, forming a group of output-input data by corresponding to the pressure value displayed by the pressure meter at that time; generating a high-frequency signal by a signal generator for controlling a control valve so as to regulate the pressure value input by the aerostatic press and obtain multiple groups of the output-input data; establishing a functional relationship between the input data and the output data; and realizing the calibration for the piezoelectric sensor. The method can accurately, simply and conveniently calibrate the piezoelectric sensor in a specific working environment. The invention also provides a piezoelectric-sensor-calibrating device.