Abstract: BP neutral network is used to improve the dependability and precision of welding line shapes model of pulsed laser welding.According to the example that 10Mn steel plate is welded using pulsed laser welding,a welding line shapes forecasting model is set up.Verification shows forecasting values and factual surveying value are almost identical,and the precision is high.The result shows this model is to be feasible and practicable.