The cable-net of FAST is a flexible cable structure with the largest span and highest accuracy in the world, also the first cable structure working in the way of active deformation as well. The cable-net comprises of 6670 main cables, 2225 node disks and 2225 down-tied cables. Imposed by 2 million load cycles, its main cable can bear a fatigue stress up to 500MPa. The manufacture error of main cable in length is controlled within 1mm at ordinary temperature(20℃). Both are far exceeding relevant industry standards. Each node disk is connected with a hydraulic actuator via a down-tied cable and anchored to the ground. The active deformation of the cable-net is realized by a coordinated stroke control of a group of actuators.