Abstract: The strong electromagnetic interference generated in the operation of the high-power TEA CO2 laser system mainly comes from the main discharge loop, pulse spark switch and power supply module. Such a strong electromagnetic interference has high interference and damage to the electronic systems inside and outside the laser system itself. The EMC of the laser system is designed based on the analysis and calculation of the electromagnetic interference to the laser system itself. The EMC problem of the high power TEA CO2 laser is settled by suppressing the propagation of the interference electromagnetic wave using two methods: one is the hardware method, the other is the software one. The hardware design way adopts electromagnetic shielding of the interference source and controlling sub-system, appropriate system layout and wiring, filtering isolation, while the software design way uses noise depression including data redundancy debugging, redundancy operation and data identification. The experimental results show that the adopted methods are effective and main ways in suppressing the interference and protecting the laser control sub-system to be damaged. Software anti-jamming is the extension and supplement of the hardware interference suppression methods, all the methods can guarantee the high reliability of the laser system.