The utility model relates to a cylindrical aerospace composite cylinder installation structure, belonging to the technical field of aerospace cylinder installation. The installation structure is fixedly connected with a cylinder and is also fixedly connected with a rocket for installing the cylinder, thus achieving the aim of installing the cylinder on the rocket. The installation structure comprises two hoops and two supports, wherein the upper and lower nozzles of the cylinder are respectively locked by one hoop and one support in a mating manner; the mated hoop and support are fixedly connected via a bolt; legs of the supports are fixedly connected with the rocket; rubber is arranged between the hoops and the cylinder as well as between the supports and the cylinder. The installation structure can select the metal nozzles of the cylinder or the cylinder body according to the installation requirements of the actual space, can achieve the installation reliability of the cylinder during no load or pressurizing, does not damage the cylinder, has a simple and light structure and is convenient to operate.