Laser transmission joining of dissimilar and biocompatible materials has potential application in biomedical implants and their encapsulation process. 0.1 mm thick PET films and 0.1 mm thick titanium are joint using laser transmission joining technology. The effects of main laser parameters including laser power,scanning speed on joint quality are investigated by using analysis of variance. The results show that laser transmission joining can be used to join PET films and titanium. Based on the research,laser transmission joining of PET film and titanium process window is obtained;it will be helpful for the premise of guarantee of joint quality.