The invention relates to a fusion protein MBP-Eppin, a protein Eppin and preparation methods thereof, and belongs to the field of biotechnology. An expression vector is built; a thrombin cleavage site He-Glu-Gly-Arg is arranged between a MBP and a target protein, so that the protein Eppin can be efficiently expressed intracellularly in the manner of combining the MBP with the protein MBP-Eppin, and the yield and the solubility of an expression product can be greatly improved; furthermore; the protein Eppin can be effectively released from the fusion protein MBP. Through a large number of experiments, the optimal condition is obtained, so that the protein Eppin can be expressed in escherichia coli in an efficient and soluble manner; meanwhile, that obvious immunoblot stripes appear on the purified fusion protein after induction and the cleaved protein Eppin are displayed; therefore, the recombined protein Eppin has excellent antigenicity.