In order to solve the problem of unstable performance of polymer bonding material in high temperature environment when fiber Bragg grating temperature sensor is encapsulated in tube, a non-adhesive encapsulation method is proposed. Quartz sleeve is selected as encapsulation material and heated by high frequency CO2 laser pulse. The transmission fiber and quartz sleeve can be reliably welded and the encapsulated sensor can be used. The temperature characteristics of the device are tested. The experimental results show that the fiber grating temperature sensor encapsulated by quartz sleeve has a good linearity between room temperature to 300 C, and can be used to measure the ambient temperature.