Aiming at the problem that speckle caused by high coherence of laser seriously affects the imaging quality, a speckle suppression method based on a singlepiezoelectric deformable mirror is proposed in this paper. A test system based on a 61-element piezoelectric deformable mirror is constructed, and the effects of surface complexity, amplitude and update frequency on imaging speckle contrast are investigated. When the number of actuators involved in the work is 61, the updating frequency of surface shape is 2.6 kHz, and the RMS of wavefront shape is 1.8 μm, the speckle contrast is reduced to to less than 4 %, at which time the scattering is significantly suppressed. The experimental results show that the higher the surface complexity, the faster the update frequency, and the larger the amplitude, the smaller the speckle contrast of the obtained image and the better the image information.