We have analyzed a five-level $wedge$-configuration Four-Wave Mixing (FWM) scheme for obtaining a high-efficiency FWM based on the two electromagnetically induced transparency. We find that the maximum FWM efficiency is nearly 30%, which is orders of
magnitude larger than previous schemes based on the two electromagnetically induced transparency. Our scheme may provide a new possibility for technological applications such as nonlinear spectroscopy at very low light intensity, quantum single-photon nonlinear optics and quantum information science.
