The invention relates to an amphiphilic alpha helix self-assembling peptide derived from SEQ ID NO:1 and an application of the amphiphilic alpha helix self-assembling peptide in protein production and purification. When the amphiphilic alpha helix self-assembling peptide and target protein are subjected to fusion expression, the amphiphilic alpha helix self-assembling peptide can induce the fusion protein to form active aggregate in cell, by comparing with polypeptide in SEQ ID NO: 1, the spatial distribution of the formed active aggregate in the cell is changed, a host cell growth state is improved, and fusion protein output is increased.