The invention relates to the technical field of numerical control machine tool machining, in particular to a cutting fluid circulating device for a numerical control machine tool and a using method ofthe cutting fluid circulating device. The cutting fluid circulating device comprises a base and a recycling barrel, wherein a liquid level sensor is fixedly arranged on the inner wall of the recycling barrel; and the cutting fluid circulating device further comprises a controller, a filtering mechanism, a proportioning mechanism and a stirring mechanism, wherein the filtering mechanism comprisesa filtering box, a shaking assembly and a pushing assembly, the proportioning mechanism comprises a storage box and a proportioning assembly, the stirring mechanism comprises a driving motor, a rotating shaft and a stirring assembly, and the driving motor, the liquid level sensor, the shaking assembly, the pushing assembly and the proportioning assembly are all electrically connected with the controller. According to the cutting fluid circulating device for the numerical control machine tool and the using method of the cutting fluid circulating device, cutting fluid contaminated on cutting chips can be fully separated out, and more cutting fluid cannot be left on the surfaces of the cutting chips, so that the utilization rate of the cutting fluid is increased, and cyclic utilization of thecutting fluid is facilitated; and meanwhile, the cutting chips in a collecting box are dried in time, so that the cutting chips can be rapidly recycled.