The invention belongs to the technical field of rocket separation, and discloses a grid wing, a novel rocket interstage section structure and application. The novel rocket interstage section structure is provided with an upper-stage rocket, the upper-stage rocket is connected with a lower-stage rocket, and the lower-stage rocket is folded with grid wings or grid rudders. The grid wings / grid rudders are manufactured in a titanium alloy SLM printing or casting or welding mode and are all installed on the top of a first-stage rocket in the circumferential direction, and the upper-stage rocket and the lower-stage rocket are each provided with a rocket engine. According to the grid wing, the novel rocket interstage section structure and the application, the multiple grid wings are installed at the position, close to the interstage section, of the upper-stage rocket in the circumferential direction, the grid wings are in a folded state before the rockets are separated, the grid wings are connected with the upper-stage rocket in a fixed-connection destructible or non-fixed-connection separable mode, and loads are transmitted to the upper-stage rocket independently or together with other interstage bearing structures. According to the grid wing, the novel rocket interstage section structure and the application, the weight is reduced, the launching cost is reduced, and the launching efficiency is improved.