Taking the finger mortise-tenon joints and dovetail mortise-tenon joints as the research target, the experimental study on the damage detection of the mortise-tenon joints under health and damage conditions is carried out based on the piezoelectric active sensing technology. Specifically, the relaxation and defects for tenons with horizontal and vertical connections are considered as the damaged cases for finger joints, while the failure process caused by testing machine is considered as the damaged load case for dovetail joints. The wavelet packet decomposition of the signal received by the piezoelectric sensor is carried out, and the damage detection index calculated as the summation of signal energy for different frequency bands is used to evaluate the damage severity quantitatively. The experimental results indicate that the signal energy received by piezoelectric sensors for finger mortise-tenon joints gradually decreases with the increase of damage severity. For dovetail joints, the tenons are squeezed tightly against each other and then the tenon is damaged as a result of its semi-rigid characteristic, so the signal energy received by piezoelectric sensors for dovetail mortise-tenon joints increases firstly and then decreases with loadings. The experiment demonstrates that the piezoelectric active sensing technology can efficiently detect the damage of the mortise-tenon joints.It can provide an experimental method for nondestructive testing based on piezoelectric sensing technology for graduate students and engineering technicians in related majors.