At the initial development stage of laser medicine, people only explored how to apply the lasers that have been mastered (argon, CO2 and Nd: YAG lasers). With the more in-depth understanding of the interaction between laser and biology and the technical development of laser and transmission system, micro channel refers to the fluid behavior at the scale of 1~1000 microns, which has been applied in chemical industry, medicine, energy, aerospace and other fields. In the process of chip production, microchannels are usually processed. Experimental data show that the accuracy of CO2 laser direct writing PMMA channel is within 5um, which can meet most medical detection applications.