Acoustic signals emitted from the keyhole are closely related to weld quality in laser welding.However,the vocal mechanism has not been clearly illustrated.In this paper,the Helmholtz resonator model,which was the initial model of kinds of acoustic components,was combined with theories of welding processing to build a new model.Numerical simulation was used to get the acoustic field.And acoustic signals were obtained through sensors.After isolating and filtering these signals,we can get data to verify the model.This will provide theoretical basis and new ideas to further study of forecasting welding qualities through the analysis of acoustic signals.