The FY3D polar orbiting meteorological satellite is the latest generation of polar orbiting meteorological satellites. Its image data contain abundant surface information such as vegetation, rivers, mountains and so on. It plays an important role in the monitoring of land resource survey and land surface type change. However, nearly twothirds of each remote sensing image is covered by clouds and fogs, so it is impossible to obtain directly surface information under the clouds for product application. The technology of data synthesis in clear sky is very important.The technology of combining three standards, i.e., minimum reflectance synthesis, maximum vegetation index synthesis and sigma synthesis, is proposed innovatively, by using the advanced synthesis technology of multitime meteorological satellite remote sensing data, the 250m resolution remote sensing data of the FY3D mediumresolution spectral imager (MERSIII) can be automatically generated, which can remove the clouds and cloud shadows.