Taking the assembly of mobile phones in the 3C industry as an example, a 6-degree-of-freedom(6-DOF)robotic arm with high degree of automation, good reliability, and high work efficiency is used to study the assembly planning of the installation of SIM cards for small electronic products for the automatic assembly line based on industrial robots. The difficulties of this process were analyzed, the assembly path was decomposed, the influence of tool posture and teaching points on assembly quality was clarified, and solutions were given, which greatly improved production efficiency. Meanwhile some suggestions are put forward to improve the development efficiency of production lines with robotic arms.