The least square support vector machine (LSSVM) was applied for the online modeling of the deformable mirror, and it could be used to forecast the wavefront control voltage at the same time. The drift characteristic of the response matrix was analyzed in the beginning, which attribute mainly to the temperature varying and nonlinearity of the actuator, and the principle of the LSSVM and its updating mechanism were introduced in the following. The optical and electro-mechanical integrated model was built in the early stage for the study of the deformable mirror, and the LSSVM model was combined into the simulation model. When the deformable mirror run in the integrated model, the control voltages and the surface profile data were collected. The data were send to the LSSVM model for the online training and updating, and the control voltages for the following step were predicted by the LSSVM model at the same time. The deformable mirror which employing 97 actuators was taken as an example to illustrate the above processes, and the simulation results were presented in details. It could conclude that the LSSVM use for the online modeling of the control voltage of the deformable mirror is adaptive and self-refreshing, so it could improve the control precision of the adaptive optical system.上海技术物理研究所创新基金(2014-CX25)