Influence function is one of the most important parameters for the correction of aberrations with deformable mirrors. When deformable mirrors are loaded with laser irradiation, the influence function will be affected by the heat-induced thermoelastic deformation, which would lower the aberration correction ability and effectiveness. On occasions when they are applied in laser systems, the influence of laser-induced thermoelastic deformation is significant, it would cause a considerable change in the influence function. We have analyzed the changes in the surface shape of a 37-element deformable mirror caused by laser induced thermoelastic deformation, and calculated the changes of influence function. The dependence of influence function on the arrangement of actuators, material properties of the actuators and the base and the heat flux is analyzed, with the actuator layout being square and hexagonal, different material properties and the heat flux varied from 0.005W/mm2 to 0.01W/mm2, using the finite element method. The results indicate that all of the previous factors will affect the influence function. Thus, in order to reduce the change of influence function caused by laser induced surface shape, the material and parameters of the deformable mirror should be chosen carefully.