<p>To explore the problem of the difference in processing effect of nanoparticles in nano-lubricants in milling and grinding of SiC_f/SiC composites. A lubricant flow rate model was established to analyze the process suitability of nanoparticles in conjunction with the model. A comparison of milling with polycrystalline diamond (PCD) cutters and grinding with sintered diamond wheels was conducted to analyze cutting force, fluctuation, cutting heat and tool wear to verify the process suitability of nanoparticles. The viscosities of graphene (GNP) nanofluid and multi-walled carbon nanotube (MWCNT) nanofluid lubricants were 0.08 Pa·s and 0.05 Pa·s, respectively. According to the analysis of the established flow rate flow rate model, the GNP nanofluid lubricant is suitable for the grinding process with low flow rate and flow velocity demand, and the MWCNT nanofluid lubricant is suitable for the milling process with higher flow rate and flow velocity demand. GNP nanoparticles have a better lubrication effect in high-pressure and high-temperature grinding due to their 2D lamellar structure. This reduces the average grinding force by 36.5%, the grinding temperature by 78.2%, and the abrasive wear of grinding wheels and chip clogging also reduced; The multi-layer tubular structure of MWCNT exerts a bearing effect to absorb the impact energy in milling, reducing the fluctuation of milling force by 14.3% and the milling temperature by 69.2%, wear zone width at the tool tip is 119.4&#xa0;μm. This study provides a theoretical basis for the application of NMQL technology in difficult-to-machine materials.</p>