The invention discloses a high-isotacticity polybutene-1 synthesis method. According to the method, the stereo-tacticity of polybutene-1 is regulated by means of alkoxy silane and ether compound external electron donors. The method comprises the following specific steps: (1) sequentially adding an alpha-olefin prepolymerization monomer, a cocatalyst, a Ti loaded main catalyst and the alkoxy silane and ether compound external electron donors into a tank reactor, and polymerizing at 5-95 DEG C for 10-100 minutes; and (2) depressurizing to remove the unreacted alpha-olefin prepolymerization monomer in the system, then introducing a butylene-1 monomer and a molecular weight regulator, polymerizing at 0-95 DEG C for 1-20 hours, and performing flash evaporation on the unpolymerized monomer to obtain powdery polybutene-1. The high-isotacticity polybutene-1 synthesis method provided by the invention is simple in process and easy to operate; the product is high in isotacticity and high in crystallization melting point; and meanwhile, the crystal form transition cycle of polybutene-1 can be also shortened.