Group delay and dispersion properties of a Gires-Tournois (G-T) etalon are deduced with the transfer matrix, the principle of using G-T etalon in multi-channel dispersion compensation is analyzed, and the cascaded G-T etalons are proposed to improve the dispersion compensation capacity. A dispersion compensation device based on cascaded G-T etalons with temperature control is introduced. When we control the inner temperature of each etalon, the refractive index of etalon can be adjusted, and the fitting for the target dispersion can be realized. The simulation is carried out with Matlab software. The simulation results show that the device could compensate all channel dispersion of both C and L bands with high dispersion compensation precision and small group delay ripple. In conclusion, the device can meet the dispersion compensation requirement of high speed optical communication system.