The effects of pixel level correction of Time Delay Integration CCD(TDICCD) on the Signal to Noise Ratio(SNR) and Modulation Transfer Function(MTF) are researched.A method to process the Pixel Response Non-uniformity ( PRNU) in a multi-tip TDICCD system is proposed based on radiometric calibration and ground management to improve the PRNU of the TDI-CCD designed. It removes Fixed Pattern Noise(FPN) of the image by the radiation calibration and corrects the strange dot in the image. By analysis of a transmitted image in real time, the pixel in the strange dot is processed and the PRNU can be managed on the ground surface in real time. Without modifying the hardware, the proposed system improves the image quality, and shows stronger correction ability for few bad pixels, low performance pixels or a few dusty pixels. By a comparison of imaging experiments, it concludes that this method corrects the SNR and MTF precisely. The correction precision has been achieved to 0.1 db(SNR) and 0.01(MTF) respectively. The image PRNU can be 1.25% when it is measured at saturation exposure of 50%. For a simpler structure, it has a better foreground in the future projects.