The invention relates to a forming method and application of a cylindrical titanium alloy dot-matrix lightweight structural component and belongs to the technical field of material processing. The forming method comprises the steps that a titanium alloy plate is made into a cylindrical piece, the cylindrical piece is placed outside an inner die, the cylindrical piece is sleeved with an outer die, and a punch is placed in a reserved loading channel of the outer die and positioned automatically; then the dies are integrally placed in hot forming equipment for stamping forming of a dot matrix position, and pressure releasing and cooling are conducted after forming is completed; and finally the cylindrical dot-matrix lightweight structural component is obtained. The high-precision and high-efficiency forming method is provided for the novel cylindrical titanium alloy dot-matrix lightweight structural component; the hot forming way of hollowing out the plate is adopted, the limitation of a composite material dot-matrix structure forming idea is broken through, the technical problem that a three-dimensional dot-matrix structure cannot be formed through metallic materials such as titanium alloy is successfully solved, the blank of the application of the dot-matrix structure in the titanium alloy field is filled, and the forming method and application have good forward-looking performance.