Titanium and its alloys have been applied in orthopedics due to their biocompatibility, mechanical, and physical properties. Here we use decyl bis phosphonate (DBP) and collagen I to modify Ti-6Al-4V through layer-by-layer technique in order to improve its bioactivity. The abilities of bovine serum albumin (BSA) adsorption and biomimetic mineralization of different sample surfaces were studied. X-ray photoelectron spectroscopy (XPS) and water contact angle data showed that DBP and collagen I were assembled on substrates successfully. The absorbance of BSA solution acquired from ultraviolet spectrophotometer (UV) indicated that samples of Ti-6Al-4V/DBP/Collagen and Ti-6Al-4V/DBP/Collagen/DBP adsorbed BSA most, followed by Ti-6Al-4V/DBP and Ti-6Al-4V. Scanning electron microscope (SEM) photos and X-ray diffraction (XRD) data showed that sample of Ti-6Al-4V/DBP/Collagen had better bioactivity in inducing HA formation than other samples tested in this investigation.