A unified physical model with the virtual element as the basic energy unit and entropy pressure as the core dynamic mechanism is proposed in this paper． The virtual element has an inherent motion property of the speed of light, with its free state corresponding to pure energy and bound state corresponding to matter． This model redefines the physical essence of time, space and gravity: time is the entropy increase process of matter returning to free energy, space is the distribution domain of entropy pressure gradient, and gravity is the generalized force induced by entropy pressure gradient． By introducing the entropy-time coupling relationship, the time dilation is directly correlated with the local entropy pressure field, and the Newtonian gravitational potential is derived under the weak field approximation, thus achieving compatibility with general relativity． The model uniformly explains the intrinsic connections of matter, energy, light, electromagnetic waves, thermodynamic laws and cosmic evolution, and puts forward testable experimental predictions． This study constructs a complete theoretical system for the unification of spacetime and matter, and provides a new feasible path for the establishment of a unified physical framework in physics．