Small angle laser scattering(SALS) is an effective measurement of the polymers spherulite radius. The conventional measurement of SALS image collection is complicated and difficult to adjust. The quality of the image is not ideal. Digital imaging technology is a good substitution, but now the main measurement is using CCD camera to collect the image directly of which the cost is high and the operation and management are not flexible. Take the advantage of CMOS imaging technology, digital CMOS camera can receive the image which is present on the ground glass by scattering light. This measurement not only reduces the cost of the hardware but also makes the operation facilitated and simplifies the SALS image collection and process.