Abstract: In order to obtain a wider plasma induced transparency (PIT) window, a dual layer tunable terahertz metamaterial structure was proposed. The transmission spectrum, electric field diagram and current diagram of the structure were simulated and analyzed. The formation mechanism of transmission window was analyzed by a mathematical model. The results show that the structure makes the move space of light-mode resonator wider and a wider transmission window can be obtained. The structure can change the width of PIT window by moving the position of I-shaped metal bar. The simulation results are well fitted with the theoretical results.