The research of reservoir fluid-solid coupling theory, especially that multiphase fluid seepage caused by water injection and exploitation, the change of stress state and the coupling between the reservoir deformations. In recent years, it caused than the great interest of chinese scholars, one of the hot topics is become the reservoir engineering and related field of research. According to the basic theory of rock mechanics, fluid mechanics in porous medium, geologic mechanics, calculated mechanics and fluid-solid coupling seepage, a mathematical and numerical model of seepage field and stress field coupling is developed in porous medium and a computer program is designed with the method of finite element technique. The Coupling Law of depressurizing exploitation Seepage field /Stress field in porous medium is studied. By the method of numerical simulation the variation law of stress-strain with time and space around borehole of impermeable rock medium, variety law of rock physical properties parameters is studied. Results show that the change of stress and strain is due to the fluid pressure of change by caused, the fluid pressure is greater, and the Stress and strain change is bigger. So from the far field pore pressure can be seen in near bottom-hole formed bigger fluid pressure, to reservoir boundaries, fluid pressure quickly cut. So, from the pore pressure of far field Pp are 15 Mpa, Pp are 21 Mpa, and Pp are 24Mpa,we can see that bigger flow pressure formed at the well bottom nearby. To the boundary of reservoir, the flow pressure decreases very quickly.