Based on the deterministic contact model, the effects of the substrate deformation, thermal deformation and asperity interaction are considered to investigate the change laws of the contact properties at interface. Firstly, a new contact model of nominally flat rough surfaces is developed to consider these effects. Subsequently, the contact area of the proposed model is analyzed through a set of research schemes. Then, the change laws of the asperity properties can be obtained through different normal displacements, sampling intervals and roughness values. The results show that the linear relationship between the contact area and the normal load agrees well with the existing work. It can lead to a decrease of the asperity-peak height and the contact area to consider the substrate deformation, compared with that of the independent asperity, the opposite is true for the thermal deformation and asperity interaction. The effects of the substrate deformation and asperity interaction will become more significant when the greater normal displacements, smaller sampling intervals and roughness values are applied. However, it is more obvious for the thermal deformation when the normal load, sampling interval and roughness become greater. It can provide a more accurate change laws for the contact properties to introduce the substrate deformation, thermal deformation and asperity interaction.