When pasted Fiber Bragg Gratings (FBGs) are used to measure bending parts, the testing results are easily affected by paste parameters. This article researches the strain transfer factors of a pasted FBG under bending parts. Firstly, a pasted FBG strain transfer model was established by theoretical analysis, and the related parameters were determined. Then, the strain transfer parameters were qualitatively analyzed by a simulated analysis method. Finally, the results of theory and simulated analysis were verified by an experimental analysis. The experiment and simulation results show that the length and the middle layer thickness of glue have dominating effects on FBG strain transfer rate under bending parts. The thickness/width of glue are secondary factors, they have a similar result for static properties, and there are small fluctuations near by 96% / 95%, respectively.When the length of glue is more than 2 times of FBG length, its static properties are obviously better than that of shorter length, and the strain transfer rate is about 95%. Moreover, the strain transfer rate of the FBG rises with the augment of middle layer thickness, sometimes even more than 100%, so it can be used to enhance the sensitization of a pasted FBG sensor. In the conclusion, the results offer a guidance for the high precision measurement of bending parts by the pasted FBGs.