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 . <EOS>