The invention relates to a simulated cutting force loading device of a head-oscillating turntable five-axis machine tool and a using method thereof. The device comprises an X-direction cutting force loading assembly, a Y-direction cutting force loading assembly, a Z-direction cutting force loading assembly, a rotary table turning-direction cutting force loading assembly, and a head-oscillating turning-direction cutting force loading assembly; and cutting force loading is realized by screwing an X-direction pre-tightening bolt, a Y-direction pre-tightening bolt, a Z-direction pre-tightening bolt, a rotary table turning-direction pre-tightening bolt, and a head-oscillating turning-direction pre-tightening bolt respectively. To be specific, the method comprises: the device is hoisted on a machine tool rotary table, the rotary table turning-direction fixed plate is fixedly connected to the machine tool rotary table, and a machine tool cutter main shaft and a motor shaft of a damping motor are fixedly connected; a group of cutting forces are set, the pre-tightening bolts of the five cutting force loading assemblies are screwed tightly by using a torque wrench, so that the friction forces of the five cutting force loading assemblies are equal to the set cutting force, and because values can not read directly by using a friction force method, screwing torques are calculated based on a formula of M=KFd/mu and then reading of values is carried out; and then the machine tool is started and processing procedures are executed, the practical operation state of the of the machine tool is simulated practically on the condition of force bearing, and the machine tool performance on the current cutting force condition is tested.