Laser speckle can seriously affect the quality of images，and can reduce the image contrast and resolution. To suppress laser speckle，based on the visual transient characteristics of the human eye and the principle of diffuse scatter speckle suppression，a small-sized laser speckle suppression device is constructed by making use of circulating colloidal solution. The device has a small volume and can effectively suppress speckle，achieving inhibition effects where speckle contrast is 5% lower than the speckle perception limit of the human eye and transmittance of light is higher than 65%. At the same time，this device has obvious advantages in reducing noise and price compared to vibration diffusers，and has certain practical promotion value.