The drilling and riveting process is widely used in the assembly of carrier rocket, which makes the efficiency and quality of drilling become the important factor affecting the assembly process. According to the problem existing in the drilling of thick laminated plate (thickness larger than 10mm) of carrier rocket, such as drill break, large noise and burr etc, experiment study of the influence of cooling conditions on the drilling were carried out. The cutting force was measured by a piezoelectric dynamometer, the aperture was measured with an outline projector and the burr was observed and measured by a digital stereo microscope. Through the measurement of contour projector and depth of field stereo microscope, the effects of three cooling conditions, including no cooling, air cooling and liquid nitrogen cooling, on the drilling were analyzed from the aspects of drilling force, diameter and burr. The results show that the largest number of hole can be obtained under the condition of air cooling. The cutting force is the largest under the condition of no cooling and that is smallest under the condition of liquid nitrogen cooling. The suddenly fracture of drill is due to the adhesions of chip under the high temperature because there is no obvious tool wear before the drill fracture.