The invention discloses a method of high-melt fluidity high-rigidity antishock polypropylene. The method is characterized by comprising the following steps: 1) under the effect of hydrogen and a Ziegler-Natta catalyst of a trialkoxyl silicane-containing compounds external electron donor, propylene or propylene and alpha-alkene are polymerized to obtain a polymer A; 2) a dialkoxysilanes compound external electron donor is added for premixing with the polymer A; 3)under the premixed material in the step 2) and hydrogen, propylene and alpha-alkene are polymerized to obtain a polymer B with melt mass flux rate of 0.01-30g/min; the antishock polypropylene comprising the polymer A and the polymer B can be finally obtained, the melt mass flux rate is 20-1000g/10min, and preferably is 20-100g/10min. The provided method has the advantages of easy operation, convenient operation and easy industrial production, so that high performance polypropylene with high melt mass flux rate, high rigidity and high antishock strength is prepared, and the high-melt fluidity high-rigidity antishock polypropylene has wide application and prospect.