The invention discloses a fusion protein of human somatostatin tetradecapeptide and human serum albumin, comprising a first region homologous with at least 85% sequence of the human somatostatin tetradecapeptide and a second region homologous with at least 85% sequence of the human serum albumin or a second region with partial amino acid sequence of the human serum albumin, wherein the first region homologous with the human somatostatin tetradecapeptide is positioned at the N terminal of the fusion protein, the second region homologous with the human serum albumin is positioned at the C terminal of the fusion protein, and no connecting peptide is added between the first and second regions; or the second region homologous with at least 85% sequence of the human serum albumin is positioned at the N terminal of the fusion protein, the first region homologous with at least 85% sequence of the human somatostatin tetradecapeptide is positioned at the C terminal of the fusion protein, and no connecting peptide is added between the first and second regions. The fusion protein disclosed by the invention prolongs the retention time of the human somatostatin tetradecapeptide molecules in the blood circulation system, and can be used for treating various diseases caused by surplus secretion of growth hormone, for treating diseases caused by endocrine disorder of gastrointestinal tract, for inhibiting growth of tumors expressing somatostatin receptors (SSTRs) and not expressing SSTRs, and for reducing the death rate caused by radiation injury of gastrointestinal tract.