Since the wavelet transformation caused a great deal of data and occupies a long time, image data compression on optical system was realized. The characteristics of optical system and optical wavelet coefficients were analyzed in detail and simulation was done on several quantization encoding methods. Then, appropriate compression method was put forward and lossy compression was realized. In addition, by analyzing the endurance to quantity noise of optical system, an important conclusion was achieved that the ideas of nearly lossless compression was sparked. Experimental results show that, compared with the directly reconstructed image, the PSNR of nearly lossless reconstructed image is only 0.1 dB, and there is no significant difference in vision.