Factors which affect the imaging quality of CMOS image sensor LUPA-4000 were investigated by analyzing the power supplies and the driving timing. Considering these factors, a CMOS imaging system with adjustable power supplies and driving timing was designed and implemented based on FPGA and ARM. Seven power supplies needed to be adjusted during LUPA-4000’s working were designed by means of the combination of adjustable resistances and corresponding power chips. Parameters used in the adjustment of LUPA-4000’s driving timing were set in PC firstly, and then transported to FPGA through Ethernet based on ARM. Actual tests showed that the imaging system can be operated and expanded flexibly, and can adjust all kinds of parameters in LUPA-4000’s driving timing precisely. Three main topics are discussed in this imaging system, including design of adjustable power supplies, methods of parameters’ setting and transmitting, and FPGA implement of LUPA-4000’s driving timing.