<p>Ti6Al4V alloy, due to its superior mechanical properties and corrosion resistance, is widely used in aerospace and medical fields. However, its processing is challenging, often leading to high temperatures and tool wear, making grinding an important machining process for Ti6Al4V. In the grinding process of Ti6Al4V, cooling and lubrication are essential. Traditional lubrication methods, such as overflow cooling, are no longer suitable due to their environmental impact and health and safety issues. Nowadays, minimum quantity lubrication (MQL) has emerged as a new cooling and lubrication technology in the industry, with vegetable oil-based nano minimal quantity lubrication (NMQL) gaining significant attention as a green and sustainable processing technique. Although experimental studies on NMQL have been successful, there is a lack of literature on the numerical simulation of MQL. In this study, a combination of finite element (FE) fluid simulation and FE grinding simulation was employed to investigate the convective heat transfer coefficient (CFTC) of the nanofluid and further analyze its cooling performance. Considering the significant influence of pressure on the grinding fluid layer, the study primarily focused on analyzing the effect of pressure as a single factor on the CFTC of the nano-fluid. A two-dimensional nanofluid simulation model was first established to analyze the CFTC of nano oil mist particles under different pressure conditions. The impact of pressure on NMQL was analyzed by combining grinding fluid layer simulation. Finally, the simulation results were integrated with FE grinding analysis to model the grinding temperature under NMQL conditions. The results indicated that with increasing pressure, the cooling performance of the nanofluid improved, and NMQL was able to reduce the grinding temperature by 32.37% to 46.58%.</p>