The invention discloses a method for producing recombinant dermatophagoides farinae allergen Der f1 and Der f2 fusion protein and relates to the technical field of construction of dermatophagoides farinae allergen gene by a biological technology. The method comprises the following steps of: obtaining a coding gene by extracting the total RNA of the dermatophagoides farinae and adopting PCR (Polymerase Chain Reaction) amplification, cutting glue to recover a product, named as Der fm, cloning to pMD19-T vectors, subcloning to expression vectors pET-28a(+), converting the vectors to escherichia coli, carrying out inducible expression by using IPTG (isopropyl-Beta-d-thiogalactoside). The method disclosed by the invention has the advantages that the consumed time is short, the process is simple, the cost is lower, the components such as a solvent can be thoroughly removed, the purity of the allergen can be increased fundamentally, the occurrence of side reaction in immunological therapy is avoided, the purity is high, the classification is clear, the accuracy of diagnosis can be increased, and a standard product is expected to be provided for novel immunological therapy.