Optical fiber embedding technology is the key to realize distributed optical fiber sensing of transformer winding. In the winding process of transformer, the copper flat wire needs to be stretched, bent and twisted to a certain extent. In this process, the optical fiber is often stretched and broken. In order to optimize the process of embedding optical fiber into the winding line of transformer, 200 m optical fiber is embedded into the winding line in the experiment, and the strain of the whole processing process of the winding line is monitored by using fiber Bragg grating(FBG), and the strain values of different links in the process of copper flat wire winding are obtained. The test results show that the maximum strain of the optical fiber in the process of copper wire winding is in the position of the take-up machine, about 4800 με, which is within the tolerable range of the optical fiber. The optical fiber is not broken and the FBG does not chirp in the whole process.