In the active vibration control field, the piezoelectric element was extensively researched with the advantages of wide response frequency band, light weight, big driving force and good linearity, but they were mainly focused on the vibration suppression for smart structure and the study on the piezoelectric element used as excitation source in the vibration test was still limited. First, according to the electromechanical coupling equation of the piezoelectric material, the piezoelectric equation when the piezoelectric ceramic applied on the one-dimensional structure like beam was derived. Then the transfer functions from piezoelectric actuator to the piezoelectric sensor were established in cases of micro-element and limited size. The quasi-independent modal control method for piezoelectric beam was studied, which made several step modals being controlled by one group of piezoelectric film simultaneously is possible. And based on this, an optimal design method for placement of sensors/actuators in the vibration test in which the piezoelectric element was used as excitation source is found.