In order to achieve long-term health monitoring for the dry air core reactor,we propose a suitable embedded fiber Bragg grating (FBG) strain sensor used in str ong electromagnetic environment.Simple structure and anti-electromagnetic interference of the strain sensor can be directly buried i n the dry air core reactor encapsulation.Two FBG strain sensors and one temperature compensated FBG sensor are embedded in the dry air core reactor encapsulation at the same time in the production process of encapsulatio n,where two FBG strain sensors are laid in the axial and radial directions,respectively.Dry type air co re reactor temperature experiment results show that the encapsulation temperature rises with the growth of power-on time and the axial strain and radial strain of 35kV dry type air core reactor encapsulation increase in the opposite directions.About five hours later,encapsulation strain is stabilized,and at this time,the axial strain is about －3200με,while the radial strain is about －4100με.The embedde d FBG strain sensor is stable and reliable,and the health monitoring of 35kV dr y type air core reactor under extreme environmental can be achieved.