Abstract: Firstly, the vibration system simulation model is established with the servo motor of the laser cutting machine as the vibration excitation source and the vibration response of the laser head as the processing accuracy evaluation parameter. The secondly, the vibration response of the laser head under multiple conditions is calculated by using the IPI and VTF evaluation methods. Then, a multi-condition and multi-objective dynamic topology optimization method is proposed, and the distribution of the beam lightening holes is optimized under the premise of controlling the quality. Finally, through the comparative analysis of the laser head vibration responses of the original beam structure, the beam without lightening holes and the optimized lightening holes under multiple conditions, it is known that: the multi-condition and multi-objective dynamic topology optimization method can reasonably optimize the distribution of the beam lightening holes, which is an effective measure to reduce the vibration response of the laser head and improve the machining accuracy. The above research results not only can provide reference for the analysis of the frequency domain dynamic mechanical properties of the laser cutting machine, but also can provide reference for the matching between the servo motor and structural performance, so have a good engineering application value.