Transmission characteristic of terahertz TE mode in twodimensional regular triangular lattice elliptic cylinder metallic photonic crystals is simulated and studied through finite element algorithm. By changing the lattice constant, length of semimajor axis and semiminor axis of ellipsoid, the transmission patterns of terahertz TE mode in metallic photonic crystal are acquired. The research results indicate that elliptic cylinder is easier to get a wide band gap than cylinder, by grouping and combining the optimal parameters, got the best band gap photonic crystals structure of TE mode. These have provided theoretic foundation for the development and production of photonic crystal bandstop filter.