The invention relates to mutant type IGF-1, a recombinant plasmid, a recombinant protein and application. The invention constructs an IGF-1 mutant, and the IGF-1 mutant and IGF-1 are combined with a receptor IGF-1R competitively, so that under the condition that other biological behaviors are not influenced, some biological behaviors of cancer cells are regulated and controlled. Through verification, the IGF-1 mutant can inhibit cancer cell migration, does not promote cancer cell proliferation, and achieves the purpose of an IGF-1 competitive inhibitor.