The occurrence of gas hydrate reservoirs is a special environment that belongs to the multiple phases. The use of two-phase porous medium theory can fully take into account the structure of the medium, the special nature of the fluid and gas that fill the pores among the mineral framework, the relationship between the properties of the parts and the entirety, which can accurately describe the actual stratigraphic structure, the attributes of strata, and the dynamic response of seismic waves in the rock. This study proposed a rock physics model based on the solid property of gas hydrate and the characteristics of the geological conditions, and constructed the equations of forward, reverse and bidirectional linear regression to calculate density.