CRISPR-Cas9 has significant influence on gene function research, agronomic traits improvement and molecular design breeding. This research successful constructed highly efficient vector pZJP049 that act as OsGW2 and OsGN1a double gene knockout. And we transformed pZJP049 into“17318”through agrobacterium mediation, obtained transformation. PCR verified positive rate in seedling is 100% . PCR-RFLP showed mutant efficiency at OsGN1a is 77.7%. PCR-SSCP showed mutant efficiency at OsGW2 is 100%. The grain size (the grain length and width) in the double mutant (gw2gw2gn1agn1a) is larger than WT. This research achieved the integration of GN1a and GW2 and precise gene editing by CRISPR-Cas9.