This paper presents a digital image acquisition and transmission methods. Using CMOS image sensors, under the control of the CPLD and microcontroller with a USB module, the system realizes the digital image acquisition and transmission. The design principle and system implementation are discussed in this paper. The system has high integration, small size and easy to install and portable .It can be well integrated with pre-processed data and image processing module , this will improve the efficiency of the computers operation. For digital image acquisition applications, size and power consumption are key considerations for hardware and software design problems, the CMOS image sensors used in digital image will have broad prospects.