The rapid flyback technology of the thermal imager has been widely used in the photoelectric searching system. The matching accuracy between the scanning rate of the thermal imager and the scanning rate of the rotary table is related to the imaging quality of the thermal imager. A two-axis turntable motion model is established in linear space. According to the coordinate transformation theory,the motion of the target relative to thermal imager in the two axis rotating table is analyzed,and a mathematical analytical equation for the scanning rate of the searching system and the scanning rate of the two-axis rotary table is derived,which provides a key theoretical basis for the application of the rapid flyback technology in thermal imager.