The invention provides a tunable dispersion compensator. A cantilever beam and a bridge type flexible hinge displacement scaling mechanism are arranged in a tunable dispersion compensator shell in a connecting mode; an adjusting leading screw of the cantilever beam passes through one side of the tunable dispersion compensator shell and is connected to the free end of the cantilever beam in an adjustable mode; an adjusting leading screw of the bridge type flexible hinge displacement scaling mechanism passes through one side of the tunable dispersion compensator shell and is connected to a displacement input end of the bridge type flexible hinge displacement scaling mechanism in an adjustable mode; an optical fiber chirped grating is fixed on the surface of the cantilever beam; and a tail fiber of the optical fiber chirped grating passes through a via hole formed at the fixed end of the cantilever beam and a through hole formed on the tunable dispersion compensator shell and is discharged from the lateral direction of the tunable dispersion compensator shell. The tunable dispersion compensator adopts a cantilever beam dispersion regulating mechanism with equal cross section and is combined with the bridge type flexible hinge displacement scaling mechanism to compensate the changes of CFG operating wavelength caused by dispersion accommodation, and the bridge type flexible hinge displacement scaling mechanism, the cantilever beam and the shell cooperate with one another to compensate the changes of the CFG operating wavelength caused by the ambient temperature.