Hot gas cleanup is a key technology of improving efficiency for IGCC and PFBC-CC systems. This paper is a study of the moving granular bed filter that is one of the greatest potential technologies for hot gas dust removal. The flow process and filtration mechanisms of the moving granular bed filter were studied, and filtration characteristics were described. Experimental studies on high temperature dust removal on the test system of the moving granular bed filter without screen had been done. The relationship between the filter characteristics and main affecting factors were found. The study showed that the moving granular bed filter can remove particles from hot gas continuously, and lead to high efficiency after optimized. This study will provide a basis for the moving granular bed filter for applications in hot gas cleanup.