The noise source and characteristics of a Solar Blind Ultraviolet Intensified Charge Coupled Device (SBUV-ICCD) are analyzed. As the single P-E(photo-electronic) response can be diffused into neighboring pixels in CCD when the system gain is to be set a higher value in working conditions,this paper takes the SBUV-ICCD as a liner and shift invariant,and imports the P-E pulse response into the calculation of SNR,then the Fourier transform is used to deduced a SNR model. This model uses a 2D Gaussian function to fit the single P-E pulse response of the SBUV-ICCD,and it is simpler than those of traditional methods. The effect of the gain on the SNR of SBUV-ICCD is analyzed and the SNR of the SBUV-ICCD is measured when the irradiance is between 10.3 pW/cm2 and 810.6 pW/cm2.The results show that the RMS of the module is 0.78,which can be used in the analysis of performance of SBUV-ICCD.