A package method of substrate fiber Bragg grating strain sensor with preload was introduced,and its sensing characteristics were studied by Ansys and experiments.The preload package was carried out for fiber Bragg grating by using aluminium alloy 7075-T6 substrate with 10mm width,22 mm length and 1mm thickness,and the sensor sensitivity of 1.05 pm/με is obtained,and the linearity is more than 0.99.The results show that the fiber Bragg grating strain sensor with preload package has good linearity and strain sensitivity,which has a guiding function for the packaging process of fiber grating sensor.