为了研究塑料激光穿透焊接的物理机理，了解焊接参数对塑料激光穿透焊接质量的影响，寻找不同条件下的最佳焊接参数，利用波长为1064 nm的光纤激光在多功能加工平台上对厚度为3 mm的聚甲基丙烯酸甲酯(PMMA)进行穿透焊接的实验研究。对焊接过程中的物理现象进行了分析，对不同激光功率、光斑半径、焊接速度下的焊接质量进行了比对，找到了这些参数对焊接质量的影响规律，并得到了几种特定条件下的最佳焊接参数。利用拉力测试仪对焊件进行了拉力测试，结果显示，焊缝的强度高于母材的强度。

To investigate the physical principle of laser transmission welding of plastics, comprehend the effect of welding parameters on the welding quality, find out the optimum welding parameters and improve the quality of plastic transmission welding, an experimental investigation of transmission welding of polymethyl methacrylate (PMMA) with 1064 nm fiber laser is carried out on the fiber laser material processing system. The physical phenomena in the welding process are analyzed, the welding quality for different welding parameters such as laser power, laser diameter and welding speed is compared. The influencing law of welding parameters on the welding quality and the optimum welding parameters under special condition are found out. The welding piece is tested by a pull testing unit. The result shows that the strength of the welding seam is higher than that of base material.