Detailed measurements of surface heat flow are needed to understand lunar thermal evolution. The insitu heat flow measurement at only one landing site is not sufficient to characterise global properties. To estimate the surface heat flow globally, an alternative and effective solution is indirectly through the study of elastic thickness Te. This study summarizes previous research and undertakes a review of Te estimation from gravity/topography admittance. Current studies indicate that the global value of lunar lithosphere elastic thickness is possibly small, suggesting the surface topography formed over a long period before the lunar lithosphere cooled. There are studies successfully estimating elastic thickness Te at some mare basins, but it is difficult to estimate Te for all of them. This failure is attributed not only to the complex selenophysical process, but also to the complexity of the lunar lithospheric compensation. It should be noted that the estimation of Te from different methods could disagree with each other, owing to the fact that Te is merely a quantity implying the strength of the lithosphere. In the forthcoming lunar exploration, an international cooperation is suggested to measure the surface heat flow globally. These measurements will not only provide optimization on the recent estimation of Te, but also be beneficial to the heat flow estimation globally and provide constraints on the lunar thermal evolution, especially with the understanding of lunar inner structure and the rheological properties of lunar crust and mantle.