Abstract: On the basis of Biot′s theory, a fluid-solid coupling problem in the case that liquid mineral, depositing in saturated porous stratum, is extracted at fixed flux is discussed. First, a decoupled method is proposed, then,the coupling pore pressure distribution and the coupling stresses, strains and displacements of porous stratum are obtained analytically. The computation of practical example indicates that there is obvious difference between the results obtained by coupling and non coupling analyses