In this study, a condition monitoring approach for the prefabricated sectional wind turbine blade with prestressed connection based on PZT is proposed and validated experimentally. The PZT actuator and sensor are mounted on the surface of the connection member to monitor the condition of the connection member which is firstly fabricated with prestressed bolts and then applied with incremental axial tensile force. A health index defined with the wavelet packet analysis on the PZT measurement is employed to monitor the connection condition. The results show that the index is related to the connection condition and changes obvious due to the separation of the connection under axial force. The proposed method is effective in condition monitoring for the prefabricated sectional wind turbine blade with prestressed connection.