As one of the biophysical parameters in terrestrial ecosystems, land cover is a basic variable that supports various scientific studies such as urban dynamic monitoring. For land cover products based on the IGBP system, this paper proposes an upscaling method based on semantic proximity and clustering rule sets. And on this basis, in view of the lack of real reference data in the current upscaling evaluation method, an accuracy evaluation index ICS based on Structural Similarity is designed. The experiments based on the MCD12C1 data of MODIS were carried out, and the results of different upscaling methods were comprehensively compared, analyzed and discussed using the proportion method and ICS respectively. The designed semantic proximity method and rule set method reached 84.1% and 84.8% in weighted ICS, respectively, and the feasibility and effectiveness of the proposed method were verified.