As a commonly used titanium alloy for marine work equipment, the TA31 titanium alloy has a low actual service life because of its low hardness and poor wear resistance. Carburizing treatment was carried out to increase the surface hardness of the TA31 titanium alloy and thus improve its wear resistance. Moreover, the effects of carburizing treatment on the microstructure and properties of the TA31 titanium alloy were studied. The microstructure, microhardness, and room temperature tensile and impact absorption work of uncarburized and carburized TA31 titanium alloy samples were compared and analysed. The results show that the microstructure of the TA31 titanium alloy before and after carburizing is a bimorphic structure, but the secondary α phase is coarsified after carburizing. After carburizing treatment, the maximum surface hardness of the TA31 titanium alloy reaches 945 HV, and the effective hardening layer exceeds 100 μm, which effectively improves the surface wear resistance of the TA31 titanium alloy. After carburizing treatment, the tensile strength of the TA31 titanium alloy decreases, whereas the plasticity of the material increases and the notch sensitivity decreases.