A piezoelectric actuating device includes a carrier, at least a piezoelectric unit, at least a linked component and a moving component. The piezoelectric unit is disposed on the carrier and includes at least a piezoelectric buzzer. The linked component is disposed corresponding to the piezoelectric unit. One end of the linked component is attached to the piezoelectric buzzer. The moving component is connected with the linked component. When the piezoelectric buzzer is actuated, it can carry the linked component to move correspondingly so as to move the moving component. The piezoelectric actuating device has the advantage of low cost and can achieve the sub-nanometer scale actuating resolution.