To provide an installation method of a strain-measuring pipe, for accurately measuring the strain of face front natural ground by burying and installing the strain-measuring pipe to which a strain sensor is attached in a stable state to the face front natural ground through a back-filling material without deformation.

The installation method of the strain-measuring pipe 10 is for installing the strain-measuring pipe 10 with the strain sensor 11 attached to the outer peripheral surface to a measuring hole 12 bored and formed in the face front natural ground 31 in order to capture the strain change of the face front natural ground 31 of a tunnel. The strain-measuring pipe 10 is almost entirely arranged in the measuring hole 12 in the state of being filled with water 13, preferably, as a filling fluid inside the strain-measuring pipe 10, and thereafter the back-filling material 14 is injected and solidified in a gap between the outer peripheral surface of the strain-measuring pipe 10 and the inner peripheral surface of the measuring hole 12. Thus, the strain-measuring pipe 10 is integrally buried and installed to the face front natural ground 31.