A piezoelectric sensor device includes a piezoelectric element, a signal processing unit, a polarization processing unit and a connection switching unit. The piezoelectric element has a piezoelectric body and a pair of electrodes sandwiching the piezoelectric body. The signal processing unit is configured to execute at least one of signal input from the piezoelectric element, and signal output to the piezoelectric element. The polarization processing unit is configured to execute polarization processing in which polarization voltage is applied to the piezoelectric element. The connection switching unit is configured to switch between a first connection state with which the electrodes and the signal processing unit are connected, and a second connection state with which the electrodes and the polarization processing unit are connected.