The present invention discloses a fusion protein for capturing mesenchymal stem cells on surfaces of targeting bone tissues, and also discloses a preparation method thereof. The preparation method comprises the following steps: (1) a Fmoc-Ser(tBu)-Wang resin is used as a start, after Fmoc is removed, a coupling agent is used to gradually couple protect amino acids, and finally, protect mimetic peptides are coupled to obtain a fusion protein-Wang; (2) peptide cutting and diethyl ether precipitation are conducted to obtain a fusion protein crude product; and (3) the fusion protein crude productis dissolved in water, pH is adjusted to 3-5, and a precipitate is collected to obtain the fusion protein. The fusion protein has good affinity with an osteogenic region, can stably bind with the osteogenic region, captures mesenchymal stem cells on the osteogenic region, promotes differentiation of the mesenchymal stem cells into osteoblasts and other bone tissue cells, and thus improves repair quality of the osteogenic region.