The invention discloses a long-chain recombination human bone pattern generating protein-2 and preparing method and application, which is characterized by the following: utilizing gene project technique to grow the protein in the expressing system of escherichia coli and bacillus subtilis; adopting human bone sarcoma cell mRNA to do reverse transcription to obtain the cDNA as form; augmenting nucleotide sequence of entire 114 amino acids naturally from carboxyl end; adding a segment of nucleotide in front of the first codon of primer 5' end; increasing a segment of polypeptide at N end corresponding to amino acid sequence; obtaining long-chain rhBMP-2 gene with molecular weight at 30KD and purity over 95%.