We implement non-equilibrium Green's function (NEGF) calculations to investigate thermal transport across graphene/metal interfaces with interlayer van der Waals interactions to understand the factors influencing thermal conductance across the interface. It is found that interfaces with a smaller interfacial lattice mismatch, lighter metal substrate and stronger interfacial bonding strength will show better interfacial thermal transport abilities. Strain induced by the interfacial lattice mismatch in graphene is the key factor for the decrease of interfacial phonon transmission in the main frequency range of metals, which finally results in a decrease of interfacial thermal conductance. A comprehensive interfacial influencing factor is proposed combining the factors of graphene density, metal density and interfacial binding energy to realize the prediction of interfacial thermal conductance across the graphene/metal interface. The results are hoped to promote the understanding of the thermal transport mechanism and design of graphene based 2D/3D materials interfaces.