A package device for applying pre-stress on a fiber grating sensor comprises, on a pedestal, a left mounting base connected with a left moving stage, a right mounting base connected with a right moving stage, a platform lifting rod sleeve arranged between the left mounting base and the right mounting base, a left lifting sleeve arranged on the left moving stage, a right lifting rod sleeve arranged on the right moving stage, a translation conversion mechanism arranged on the left and the right moving stages, a left lifting rod arranged on the top of the left lifting rod sleeve and connected with a left clamp frame, a right lifting rod arranged on the top of the right lifting rod sleeve and connected with a right clamp frame, and a platform lifting rod arranged on the upper end of the platform lifting rod sleeve and connected with a platform. The package device has the advantages of simple mechanical structure, small size, low cost, easy operation, etc., and can be used in a temperature range of subzero 25 DEG C to above-zero300 DEG C to achieve high-temperature curing package when applying pre-stress to a fiber grating. The fiber grating sensor packaged by the device has no chirp and waveform aberration, thus ensuring the repeatability and the linearity of the sensor.