In order to further explore the simulation of nanofluid heat pipe, the VOF(volume of fluid) model in Fluent software was used to take single nanofluid (TiO2-H2O) and mixed nanofluid (Al2O3+TiO2-H2O) as working medium. The feasibility of using Fluent to simulate nanofluid heat pipes was comprehensively analyzed from the visualization analysis of evaporation and condensation process inside heat pipes and the results of the overall thermal parameters. The results show that, from the visualization point of view, the simulated nephogram can reflect the phase transition process in the heat pipe with time. However, there is still a 3% error between the specific simulation value and the corrected experimental value, indicating that there are unconventional factors affecting the simulation results. It is feasible to use the VOF model to simulate the nanofluid heat pipe in numerical law and visualization analysis, but it is still necessary to combine other simulation methods to study the detailed principle.