Abstract: The molybdenum gradient modified layer was prepared on the surface of TA2 pure titanium substrate by double glow plasma surface alloying technique. The cross section morphology and element distribution of the modified layer were analyzed, and the microscale quasi-static contact mechanical property of the modified layer were studied. The results show that the molybdenum gradient modified layer was uniform and compact with the thickness of 12 μm, and was composed of the deposition layer with 2.7 μm thickness and the diffusion layer with 9.3 μm thickness. The content of Mo and Ti element changed in gradient along the thickness direction, and the modified layer had a good metallurgical bond with the substrate. The hardness and elastic modulus of the modified layer were 13.82, 142.96 GPa, which were 10.87, 142.38 GPa larger than those of the substrate, respectively, indicating that the modified layer had high strength and good plasticity. When the test load was 15 N, the micro-indentation depth was nearly 15 μm, and the composite hardness and elastic modulus were close to those of the substrate, indicating that the strengthening effect of the modified layer was completely ineffective.