A fiber grating two-dimensional displacement monitor comprises a shell body and further comprises a first assembly and a second assembly. The first assembly is arranged outside the shell body, the second assembly is arranged inside the shell body. The second assembly is provided with cantilever beams where grating optical fibers are adhered. The fiber grating two-dimensional displacement monitor is buried in soil, by means of displacement changes of the first assembly, transformation of fiber grating of the second assembly is detected, and conditions of landslide, dam body deformation and roadbed settlement are measured. Therefore, the grating two-dimensional displacement monitor can carry out multi-point real-time monitoring in a long distance, can effectively reduce labor and material cost with remote real-time monitoring, can effectively avoid influences of weather or other human factors on monitoring, and intensifies reliability of measurement data.