Abstract: The effect of active impurity on double barrier photonic quantum well filter was studied by transmission matrix method. The results show that when there was no active impurity in medium, the quality of double barrier quantum well filter increased with the periodicity of barrier layer increase, and the frequency of filtering channel shifted at same time. When there was active impurity in inner-barrier and well layer respectively, the resonant tunneling modes appeared high magnification, but the frequency of tunneling modes were constant. The quality of quantum well filtering increased quickly with the increase of value of imaginary part of dielectric, especially when there was active impurity in well layer, the quality reached 8.010104. These properties can achieve functions of high-quality optical filtering and optical signal amplification, providing positive guidance for design and application of photonic quantum well.