Abstract: Aiming at the simulation of rock deformation in mining protection applications, a two-dimensional rock mass model based on deterministic finite cell automata is proposed. This model uses automata theory to describe the internal and surface settlement distribution of rock masses, and can obtain the settlement trough profile in a relatively simple way. The profile is consistent with the geodetic observation profile. Based on the existing cellular automaton solution, a horizontal displacement simulation optimization method based on the propagation function concept was proposed by adding a copy of a subsidence grid to the second cell grid of the model. The method can simultaneously simulate the horizontal displacements on the interior and surface of the settlement and rock mass models. In addition, a ratio formula for describing the maximum horizontal displacement and the maximum settlement was determined. The deformation distribution of 300m 800m rock mass caused by coal seam extraction was simulated. The results show that the settlement and horizontal displacement results of the proposed model are consistent with the geometrical integration theory, and its feasibility is verified.