Abstract: Gas hydrate production from reservoir by depressurization is a non-isothermal flow process in porous medium involving hydrate phase change and fluid-solid coupling.The existing study on production of gas hydrate reservoirs is mainly limited to productivity simulation,without consideration of fluid-solid coupling effect.Due to hydrate decomposition,the near wellbore formation of hydrate bearing layers will have weak consolidation,low strength and high porosity and permeability.And the stability of the near wellbore formation shall be taken seriously but the relevant researches have not yet begun.Therefore,incorporating the effect of gas hydrate dissociation into the interaction between porous fluid flow and rock deformation,a gas-water two-phase non-isothermal fluid-solid coupling model was established and a corresponding finite element program was developed based on the sand production criterion.The general rule of the stability of near wellbore formation of hydrate reservoirs has been analyzed,and a method for critical drawdown pressure determination has been proposed.The research shows that the effect of gas hydrate dissociation is the dominant factor affecting the formation stability and the effect of the fluid-solid coupling on stability is negligible.The stability of near wellbore formation is relatively weak and the wellbore in the direction of minimum horizontal ground stress is in the worst in stability,where the sand production may occur first.The stability of the transient area is between the dissociation area and the undisturbed formation.