Aiming at addressing the technical difficulties in the determination of trace silver in mine tailings, an energy dispersive X-ray fluorescence energy spectrum method based on ultra short optical path is proposed. It improves the measurement resolution of the elements, the efficiency of sample analysis and reduces the power of the light tube. What’s more, it extends the service life of the instrument. Energy spectrum system optimized filter, detector shielding design. Besides, since Teflon has no X-ray scattering as collimator , the detection of trace elements for silver is achieved. In actual tailings test, silver detection limit is up to 1 mg·kg-1. RSD is between 01 percent and 26 percent while accuracy is between 115% and 87%. With the comparison of tailings, ore and concentrate test experiment, it is proved that the energy dispersive X-ray fluorescence spectrum which introduced in the method of ultra short optical path can enhance the system peak/background ratio and satisfy the requirement of the detection of trace element.