Signal process system composed of visible information process circuit and infrared information process circuit is applied in a space-born multi-spectral Sensor. Based on pushbroom image, the system with external synchronization completes driving and signal processing of detectors including visible, short-wave and middle-wave infrared as well as long-wave infrared. Sampling and processing of analog signal along with integration and format of digital signal are also completed in the system. Multi FPA(focal plane array) synchronization, large number of analog outputs, high signal to noise ratio are characteristics of the systems. Eventually, the system samples 32 analog video signals and outputs 14bit data by 5 serial LVDS channels with a 30Mbps transmission rate in single channel. Under given test condition in laboratory, the results indicate that the SNRs of visible and short-wave infrared channel are 307 and 422, meanwhile the NETDs of middle-wave and long-wave infrared channel are 0.14K and 0.16K. An imaging experiment in VIS channel acquired good image data. The regular test and imaging experiment results validate that the system can meet the demands of multi-spectral sensor application.