The use of analog 4-binning mode in Mars mineral spectrum analyzers enables the instruments to deal with the complex environment in deep space and hence to meet the requirements of high signal-to-noise ratio and large dynamic range. A new on-chip 2×2 pixel binning driving method is proposed and the rationality of its output is verified. For an e2v CCD 47-20 chip, the CCD structure is studied and the 2-binning methods both in horizontal direction and in vertical direction are designed so that the driving wave can be controlled by FPGA. On the basis of the structure of a CCD on-chip amplifier, a four-stage model is obtained by simulating the 2×1-horizontal output analog signal model. The result obtained in the uniform light illumination experiment shows that the CCD output signal in the 4-binning mode is the same as the simulation result. This confirms the CCD amplification theory. The output voltage presents a linear trend when the value is than 600 mV, which proves that the combined results of the scheme are accurate and reliable.