Today, the world's largest thrust and engineering application integral solid rocket motor was successfully tested at the Fourth Academy of Aerospace Science and Technology Group. The motor has a diameter of 3.5 meters and a thrust of 500 tons. It adopts a high-performance fiber composite casing, a high-load integrally molded combustion chamber and a large nozzle. The success of the test indicates that China's strong loading capacity has achieved a significant increase. The upgrade is of great significance to promote the development of large and heavy launch vehicle technologies in the future.