The invention provides a detachable internally-arranged infrared temperature measuring device for the GIS. The detachable internally-arranged infrared temperature measuring device for the GIS comprises an infrared perspective window, an infrared temperature measurement sensor body, a fully-sealed shell, a first installation flange, a second installation flange, a circuit protective shell and a signal amplifying and processing circuit. The infrared perspective window is connected with the infrared temperature measurement sensor body. The infrared temperature measurement sensor body is located inside the fully-sealed shell. One end of the fully-sealed shell is fixed to the GIS through the first installation flange and the other end of the fully-sealed shell and the circuit protective shell are connected through the second installation flange. The signal amplifying and processing circuit is located inside the circuit protective shell. The detachable internally-arranged infrared temperature measuring device for the GIS is flexible and detachable, the infrared temperature measurement sensor body and the fully-sealed shell are safe and independent, the sealing performance and the voltage resistant performance are good, and the infrared temperature measurement sensor body and the fully-sealed shell are installed outside a GIS air chamber, so that verification, maintenance and replacement which are conducted by an infrared temperature sensing system are facilitated under the condition that the GIS is operated; the device can be detached under the condition that normal operation of the GIS is not influenced, an internal electric field structure of the GIS is not influenced, and the requirement for the sealing performance of the GIS is satisfied.