Based on the physical and mechanical characters of micro-heterogeneous material such as rock and concrete,a new theory of physical cellular automaton (PCA) for simulating the failure evolving process of micro-heterogeneous materials is set up,according to the basic law of the transfer of energy.PCA breaks through the traditional cellular automaton method which is only a mathematical operation.It is shown by some laboratory tests that the simulating results by PCA can agree with the laboratory results perfectly,thus,PCA is an effective physical and mechanical method.