Abstract: Based on the pulsed Gaussian laser as light source and one-dimensional ZnO materials with 500 nm ~ 1000 nm diameter and 10 m length as target, the finite element analysis software ANSYS was used to establish the thermodynamic simulation model of laser cutting ZnO nanowires. The birth-death element technology was adopted to process the unit which temperature was above the melting point. The temperature distribution field and the cutting morphology were obtained, as the laser working parameters and ZnO nanowire diameters changed. The influence of the nanowire diameter and the focusing spot displacement relative to the nanowires on laser cutting was discussed. The results show that the larger the nanowire diameter is, the smaller the tolerance of the laser defocus amount is; when the defocus amount is zero or the negative defocus is small, a better cutting morphology is obtained.