Abstract: On the basis of analyzing the preparation method of hydroxyapatite (HA) and the diffluence method of silk fibroin fibre (SF)，a  “one-step” method that is used to prepare nano hydroxyapatite/silk fibroin biology composite (SF/HA) was  put forward. The SF/HA composite was observed and tested by FTIR, TEM and XRD.The ratio of calcium to phosphorus in the SF/HA composite was tested by the chemical method.The results show that the ratio of calcium to phosphorus in the SF/HA composite is 1.6692, which  is the same as 1.67 in HA.The function groups in both HA and SF were discovered in the SF/HA composite. The SF/HA composite crystal particle is of spiculate or column configuration. The crystal size of the SF/HA composite is less than 100 nm in the horizontal direction. The HA and SF composite can come into being. The HA/SF composite is hexahedron crystal.When the mass fraction  of SF in SF/HA was 10%，the crystal cell parameter of the SF/HA composite crystal is a=b=90319 A，c=7.0148 A. The average crystal size of SF/HA along the c axes direction is 230.7645 A. So the “one-step” method is rational and feasible.