The effects of short-time electromagnetic stirring(EMS),grain refiner and their combined effects on microstructure and radial homogeneity of large-volume semisolid slurry of 7A04 alloy were investigated.The results indicate that 7A04 alloy semisolid slurry with fine and globular primary α-Al grains could be achieved and the homogeneity of slurry could be improved by either short-time EMS or addition of grain refining element Zr,Sc. Optimum microstructure with average equivalent diameter of 36um，shape factor of 0.68, coefficient of variation Cv of 0.8% at 631℃ could be obtained by the combined action of short-time EMS and grain refiner.As the temperature decreased,microstructure of semisolid slurry of 7A04 alloy coarsened and homogeneity of microstructure of slurry deteriorated,while the shape factor had little change.