A method for generating operation simulation information of a numerical control device being a cutting tool equipped with a cutter, the simulation information relating to an on-site operating scenario of a digital factory, wherein the method comprises the following steps: a) acquiring physical operation information of the numerical control device comprising axial position of a machine tool spindle, spindle rotation speed, cutter serial number, feeding speed and cutting torque; and b) acquiring model information corresponding to the numerical control device including acquiring, from a model provision apparatus, CAD 3D model information of a spindle, linear axle, clamping cutting tool, and product being cut; c0) driving the cutting machine model of the numerical control device to execute an operation, corresponding to the real cutting machine, according to the physical operation information; c) generating operation simulation information of the numerical control device on the basis of the physical operation information and the model information, outputting the operation simulation information to a client, outputting the operation simulation information to a user in visual form of an image or moving picture, and generating a virtual reality, VR, device readable form therefrom; d) wherein the model information comprises model information i) of various components associated with operation of the numerical control device, which comprises a model corresponding to each component in the numerical control device, and ii) an operation object thereof; e) wherein the method further comprises the following step: - acquiring time information corresponding to the physical operation information, wherein the step of generating and outputting operation simulation information further comprises: - receiving designated time information from the client; - generating operation simulation information corresponding to the designated time information and outputting the operation simulation information to the client. a) acquiring physical operation information of the numerical control device comprising axial position of a machine tool spindle, spindle rotation speed, cutter serial number, feeding speed and cutting torque; and b) acquiring model information corresponding to the numerical control device including acquiring, from a model provision apparatus, CAD 3D model information of a spindle, linear axle, clamping cutting tool, and product being cut; c0) driving the cutting machine model of the numerical control device to execute an operation, corresponding to the real cutting machine, according to the physical operation information; c) generating operation simulation information of the numerical control device on the basis of the physical operation information and the model information, outputting the operation simulation information to a client, outputting the operation simulation information to a user in visual form of an image or moving picture, and generating a virtual reality, VR, device readable form therefrom; d) wherein the model information comprises model information i) of various components associated with operation of the numerical control device, which comprises a model corresponding to each component in the numerical control device, and ii) an operation object thereof; e) wherein the method further comprises the following step: - acquiring time information corresponding to the physical operation information, - acquiring time information corresponding to the physical operation information, - receiving designated time information from the client; - generating operation simulation information corresponding to the designated time information and outputting the operation simulation information to the client.