Speckle noise removal is the most difficult part of the de-noising op eration in the phase unwrapping of digital holographic interferometry.In order to get better de-noising algorithms,speck le noise with different signal to noise ratio (SNR) shou ld be produced.This study proposed a method that uses liquid crystal spatial lig ht modulator (LC-SLM) to generate a scattering object with adjustable roughness and different signal-noise ratio speckle field .Experimental results of the probability density distribution,the contrast of speckle intensity and the probability density dis tribution of the speckle phase are in good agreement with the theoretical calculation values.It is concluded that generatio n of scattering object with LC-SLM is viable. Moreover,this method has the advantage that the roughness of the scattering object is adjustable in a certain range.