Focusing on LCOPA（Liquid Crystal Optical Phased Array）beam steering characteristics with high power laser incidence, the thermodynamic model of liquid crystal optical phased array is established in this paper. According to Ericksen Leslie theory and temperature characteristics of liquid crystal materials, the phase distribution in near field, deflection efficiency in far field and response process of LCOPA are analyzed by numerical method under the condition of different incident and different liquid crystal materials. As a result, when the incident laser power increases from 50 W to 110 W, the phase distribution in near field tends to deteriorate and the deflection efficiency in far field decreases from 96.8% to 41.3%. Among three liquid crystal materials, 5PCH, UCF-35, MLC-624-000, the deflection efficiency in far field is 41.3%, 92.3% and 98.8%, respectively, with their temperature sensitivity gradually decreasing. Meanwhile, when incident laser power rises, the drop time of LCOPA is shortened and the rise time and switch time are not significantly affected.