The invention relates to a physical simulation method for achieving a thermal recovery process of an indoor core, and mainly aims at solving the problems that an existing indoor thermal recovery simulation method is complicated in system composition, relatively multiple in input devices and unstable in experiment process. The physical simulation method is characterized by comprising the following steps: (1) determining gradient distribution of crude oil viscosity in the core according to the viscosity-temperature relationship of the crude oil and setting into n parts; (2) punching an epoxy resin casting core and dividing the core into n regions; and (3) sectionally saturating the crude oil with different viscosities from an inlet end of the core until the crude oil with n parts of viscosities is saturated. The physical simulation method for achieving the thermal recovery process by the indoor core is simple in technique; and the thermal recovery process is simulated by highly simulating the saturated crude oil with different viscosities in various regions of the core under the formation porosity condition.