Piezoelectric deformable mirrors(PDM) is a widely-used wavefront corrector in the adaptive optics which is to compensate for the wavefront aberration generated by the atmosphere turbulence in astronomical telescopes and laser communication systems. Analyzing the performance parameters of PDM,like fitting error,actuators′ number and spatial arrangement,dynamic range,we designed an experimental adaptive optic system based on 19-channel PDM. This system uses Zernike modal approach to reconstruct the wavefront and real-time control PDM to compensate three wavefront aberrations:defocus,astigmatism and coma simulated in Matlab in a negative feedback closed loop. The experimental results show that the piezoelectric deformable mirrors have good correction capability for wavefront aberration in negative feedback closed-loop adaptive optic system.