7 alpha-Hydroxysteroid dehydrogenase (7 alpha-HSDH) is one of the key enzymes in the catalytic reaction of taurochenodeoxycholic acid (TCDCA). To improve the activity of immobilized 7 alpha-HSDH, the microenvironment of immobilized 7 alpha-HSDH was modified with epoxy resin and ethanediamine (EDA). The amino-epoxy support was characterized by Fourier transform infrared (FTIR), Spectrometer elemental analysis (EA), scanning electron microscopy (SEM), contact angle (CA), and Zetasizer. The effects of the immobilization of 7 alpha-HSDH on the amino-epoxy resin and epoxy resin were studied. The results indicated that the relative activity of immobilized 7 alpha-HSDH on the amino-epoxy resin increased by approximately 80%. Meanwhile, the immobilized 7 alpha-HSDH showed favorable thermal stability and operational stability. The thermal stability of immobilized 7 alpha-HSDH increased at temperatures ranging from 15 to 35 degrees C, while the relative activities of 7 alpha-HSDH immobilized on the amino-epoxy resin and epoxy resin retained 56.4% and 61.0%. After 6 cycles, the residual activities of the 7 alpha-HSDH immobilized on the amino-epoxy resin and epoxy resin were 81.4% and 89.5%, respectively.