Emplacement of granitic magma causes contact metamorphism and brittle deformation in host rocks. These fractures provide important pathways for fluid activity and element migration. However, most magma emplacement models ignored the influence of thermal convection. Here we summarize numerical simulation principles of magma emplacement and compare different simulation methods. Using the MatDEM discrete element software, we establish a double- layer host rock model and a homogeneous host rock model. The pore- density flow method of MatDEM was applied to simulate the fluid- solid- heat- stress coupling process during intrusion and cooling of granitic magma. The results reveal three stages of the fracture development and heat transfer patterns during magma emplacement. ① During initial intrusion, compression of magma produces the widespread, radial distribution of shear fractures in host rocks. Heat conduction and infiltration are dominant in host rocks. ② Under continuous pore fluid pressure, the radial shear fractures are connected and form major extensional fractures, which become important pathways of melt and fluids and provide space for pegmatitic and hydrothermal ore deposits. Channel flow and localized thermal convection control heat transportation in host rocks. ③ In the last stage, increase of the pore fluid pressure in host rocks around the magma chamber triggers large amounts of tensile fractures, which enhance the thermal convection in the contact aureole and promoting skarn- type mineralization. Compared with the thermal conduction model, initial thermal convection will decrease the width of the contact aureole. The geometric shape of a contact aureole is controlled by the shape of intrusion, but its width shows remarkable spatial variations. Our modeling results provide a new way to reconstruct metamorphism, deformation and mineralization during magma emplacement.