Picosecond laser processing has the characteristics of high peak energy and short pulse action time,which is an important means of cutting holes in carbon fiber reinforced polymer(CFRP).However,the thermal physical properties of carbon fiber and resin matrix are quite different,and the laser pulse energy accumulation and conduction behavior make thermal damage difficult to avoid.In this paper,a kind of picosecond laser cutting CFRP technology assisted by dimethicone is proposed to study the effect of dimethicone on the internal defects,heat affected zone(HAZ),hole roundness and taper.The results show that the quality of dimethicone assisted hole cutting is significantly improved compared to picosecond laser cutting.And there is no matrix damage at the notch,no crack on the inner wall of the hole,and still slight fiber exposure.HAZ on surface is reduced to 4.1μm(laser repetition of 200 kHz,scanning speed of 1800mm/s).The taper is reduced by 16.09% at a laser repetition frequency of 200 kHz and scanning speed of 600mm/s.In conclusion,dimethicone is helpful to control the damage of CFRP laser cutting which improving the micro defects,suppressing the HAZ,and reducing the taper.