A novel optical tunable filter based on liquid crystal technology is reported in this paper. The structure and principle of this novel liquid crystal tunable filter are presented carefully, and then the optical signal transmission matrix and expression are deduced by the Jones Matrix way, the modulated characteristics of the LCTF′s amplitude and phase are achieved by numerical simulation. The DGE based on eight cascaded LCTFs are analyzed and emulated with genetic algorithm, and the experiment of DGE is realized with the parameters of the simulation results, the whole optical transmission spectrum are gained, and these experimental results agree well with the theoretical analysis.