The coupling problems of aeroheating and solid heat penetration are very important to aerospace and engineering applications. The loosely-coupled and the fully-coupled methodology are both applied to simulate a two-dimensional hypersonic fluid-solid thermally coupled flow around a cylinder. The unsteady Navier-Stokes equations and the 2D unsteady heat-conduction equation are derived, solved by the finite volume and the Galerkin finite element methods respectively. The coupling is processed by the boundary conditions of heat flux and temperature at the fluid/solid interface. The flow part is solved by AUSM+ and explicit multi-step Runge-Kutta method. The results are compared with the experimental data and computational results from the reference. The method is shown to give good predictions of the temperature variation and heat flux distribution, and the loosely-coupled method is shown to be more efficient and similar accurate if the characteristic time for fluid is far less than the time for solid.