Speckle noise in digital holography has a great influence on image quality, and one of the reasons for the formation of speckle noise is that the coherence between reference light and object light is too high, which leads to speckle effect and introduces unnecessary noise to recorded hologram. Speckle denoising is realized by using electrically controlled liquid crystal scatterers to decolorize coherent light. By adjusting the voltage to change the scattering effect of the electrically controlled liquid crystal scatterer in the object light path, the holograms irradiated by the liquid crystal scatterer under various scattering effects are recorded, and the equivalent appearance index of the reconstructed object image under various scattering effects is different, and the optimal result is obtained through comparative analysis. Then the hologram is reconstructed by superimposing the hologram under the optimal scattering effect and the effect is better than that of the single image. Through theoretical analysis and experimental verification, it is proved that the proposed method has great application value to improve the imaging quality of digital holographic system.