Marine structures often suffer from biofouling, which may lead to macrofouling by marine animals like marine worms and barnacles, weighing down the structures and increasing the drag. This paper analyses the effect of the newly fabricated biological anti-adhesion Titania-Polyurea spray coating, which can effectively reduce biofouling from enriching on the surface. Through the surface characterization, bioassays and micro-channel drag-reduction test, the antibacterial effect caused by the nano-titanium dioxide is systematically studied. Compared to the different weight percentages of nano-TiO₂ in the coating system, the photocatalytic activity, riblet surface structure and hydrophobic wettability are supposed to be the key factors to reduce the flow resistance at a drag reduction rate of 3.0% and further enhance the anti-biofouling performance under dark conditions.