In order to accurately obtain the structural state of the railway track,improve the sensitivity of the test point and suppress the interference,a condition monitoring system based on the optical fiber Internet of Things is built,and a FBG sensor package is designed that can suppress stress interference at the non test position.The system enables wide range monitoring of track structure status over long distances through multi channel optical switches and wavelength division multiplexing technology.The non sensor insensitive to stress response at the test location is made by the delta package design.The stress field distribution after wheel crush on the track is simulated and analyzed.The stress changes in the directions of the three coordinate axed at the test positions at different times are analyzed,with a maximum of 186.2 με in the x axis.The quantitatively analysis of the sensitization effect of the optimized FBG packaging structure designed in this paper shows a sensitivity of 20.1 pm/kN,which is nearly 8 times higher than that before the optimization.In the temperature drift compensation experiment,it is verified that the temperature compensation can effectively suppress the wavelength shift caused by the temperature change of the test environment in both unstressed and stressed states.From the dynamic test curve,the strain response of the test position can be accurately extracted,and the maximum wavelength shift is 253.2 pm,which meets the design requirements.