In order to analyze the noise level of FY2 VISSR VIS channels using the space areas data on FY2 VIS full Earth disk imagery,space structure function analysis was used. The results show that the noise level of FY2 VISSR VIS channels are not the same,the equivalent noise level of CH1 is 0.51,and the equivalent noise level of the other channels are from 0.42 to 0.45.