An integrated online measurement system for thermophysical property parameters of nanofluid cutting liquid, consisting of a gas path system, a liquid path system, a nanofluid heat conductivity coefficient measuring device, a nanofluid cutting liquid convective heat transfer coefficient and fluid/workpiece energy ratio coefficient measuring device, and a grinding force and grinding temperature measuring device or a milling force and milling temperature measuring device. The nanofluid heat conductivity coefficient measuring device is located in the liquid path system; the guras path system provides presse for nanofluid in the liquid path system, and two nozzles are led out from the liquid path system; the nanofluid spray ejected by the nozzle I is sprayed onto the surface of a workpiece I, so as to form the nanofluid cutting liquid convective heat transfer coefficient and fluid/workpiece energy ratio coefficient measuring device; and the nanofluid spray ejected by the nozzle II is sprayed onto the surface of a workpiece II, so as to form the grinding force and grinding temperature measuring device.