The present invention discloses an integrated online measurement system for thermophysical property parameters of nanofluid cutting fluid, consisting of a gas path system, a fluid path system, a nanofluid thermal conductivity measurement device, a measurement device for a convective heat transfer coefficient and a nanofluid/workpiece heat partition ratio of the nanofluid cutting fluid, and a grinding force and grinding temperature measurement device or a milling force and milling temperature measurement device; the nanofluid thermal conductivity measurement device is located in the fluid path system; the gas path system provides pressure for the nanofluid in the fluid path system, two nozzles lead out from the fluid path system, and the nanofluid gas spray ejected by the nozzle I is sprayed onto the surface of a workpiece I to form the measurement device for the nanofluid convective heat transfer coefficient and the nanofluid/workpiece heat partition ratio; and the nanofluid gas spray ejected by the nozzle II is sprayed onto the surface of a workpiece II to form the grinding force and grinding temperature measurement device.