针对聚合物在汽车轻量化应用中引发的连接需求,采用NdYAG脉冲激光器对车用材料聚甲基丙烯酸酯（PMMA）进行激光透射点焊实验研究。利用响应曲面法建立工艺参数与最大拉力和熔池直径的数学模型，并进行实验设计优化与分析。分析了作用时间、离焦量、峰值电压、脉冲频率对连接性能和熔池直径的影响，并采用两种优化准则进行优化分析。结果表明，峰值电压和脉冲频率是通过控制激光功率来影响连接性能，且后者对激光透射点焊连接性能影响较大；当激光功率较大时，能量密度较为集中，增加激光作用时间易造成材料烧蚀甚至穿透。工艺优化过程中，预测值与实验值相对误差保持在8%以内，优化的预测结果与验证实验的结果较为吻合，对提高连接质量和降低生产成本有很好的指导意义。

To quantify the need for the connection of a lightweight polymer in the automotive industry, the study on laser transmission spot welding of material PMMA for vehicle by NdYAG pulse laser is conducted. The mathematical model of the process parameters with the maximum tensile force and molten pool diameter is established by the response surface method, and it can be used to optimize and analyze the experimental design. The interaction effects of key parameters including voltage, frequency, stand-off distance, and exposure on the joint performance and the mean weld diameter are analyzed, and the optimization analysis is carried out based on two kinds of optimization criteria. The results show that the voltage and frequency can affect the joint performance by controlling the laser power, and the latter has a significant influence on laser transmission spot joining performance. When the laser power becomes higher, the energy density is more concentrated. In that case, if the laser action time increases, it is easy to initiate ablation or even penetration of samples. In the process of optimization, the relative error between the predicted value and the experimental one is less than 8%, so the predicted results of parameters optimization are consistent with the experimental ones. Above all, this study provides an effective direction to enhance the bond quality and minimize the bond cost.