Abstract: The types and nature of the Indo-Australian plate are very complex.A 3D lithosphere model of the Indo-Australian plate is constructed and numerical simulation of the tectonic stress field of the Indo-Australian plate is performed by using the pseudo-3D finite element method and adopting the WSM2000 observed stress data and stress state as constraints,and then the influence of the boundary forces applied at the Indo-Australian plate on the intraplate stress field is discussed.The results show that the intraplate tectonic stress field of the IndoAustralian plate is mainly controlled by two factors:(1) the asthenospheric static push;and(2) the resistance coming from collision zones,including Himalaya,Papua New Guinea,New Zealand and the northwestern boundary between the Indo-Australian plate and Eurasian plate.However,the effect of the extensional forces from the subduction zone on the intraplate stress field is relatively small.