The invention discloses a method for preparing a carbon boron nitrogen doped double-tube titania nanotube array from ionic liquid on a titanium base, which comprises the steps that ionic liquid and organic solution are used as electrolyte, a titanium sheet is used as an anode, a platinum sheet is used as a cathode, the titanium sheet is anodized in ultrasonic bath, a carbon boron nitrogen doped double-tube TiO nanotube array is synthesized on the titanium base by self-assembly, and the sample is calcined in a nitrogen atmosphere tube furnace after washed and dried. The invention further extends light response range and enhances response capability to visible light through three-element doping, saves energy and has the advantages of simplicity in operation, adjustable design and composite structure, and high practical application value.