The construction and operation of subways causes different degrees of impact on the ground， particularly the construction of subways on islands， which have complex topographic and geomorphological environments， unstable soil layers， and ground deformation that is difficult to analyze. The objective of this study was to solve these problems. In this study， using the 38-view image data of Sentinel-1 and tunnel point-cloud data collected independently， the permanent scatterer synthetic aperture radar measurement technology， differential interferometry short baseline set time-series analysis technology， and LiDAR technology were employed to study the area along Metro Line 2 within Xiamen Island. The accuracy of the results of these two techniques based on synthetic aperture radar were compared with level data to verify their accuracy. Finally， the results of deformation were compared with the results of the LiDAR technique to obtain point-cloud data by scanning the tunnel inside the subway. The experimental results show that the deformation rate based on PS-InSAR technology ranged from -24.21 to 24.19 mm/y， whereas the deformation rate based on SBAS-InSAR technology ranged from -22.86 to 33.79 mm/y； the two methods were essentially identical in the process of deformation monitoring. The comparison with the level measurement results indicate that there was an error between the two. The error was concentrated within ±7 mm and was approximately 13 mm for some of the distances from the level. Meanwhile， the settlement range of the underground tunnel was -43.4 to 104.1 mm， with a medium error of 28.44 mm， and the result differed significantly from those for the ground deformation. After several verifications， it was confirmed that the underground rail transit tunnel is less affected by the ground deformation.