A cholesteric chiral artificial receptor L5 was synthesized, which recognized and cooperated with Ag+ in metal ions, and a rapid method for detecting Ag+ was established in food. It was found by fluorescence spectroscopy anal. that the L5 could recognize Ag+ in DMSO solution; with the help of fluorescence and UV titration, job test and interference test to verify its recognition pattern, and founded that the L5 and guest Ag+ were combined with 1:1 coordination ratio. Then, the recognition mechanism between L5 and guest Ag+ was explored by measures of nuclear magnetic titration, IR spectroscopy, electron microscopy and computer mol. simulation. It was speculated that the carbonyl oxygen atom near the amide of the MeO-PhCONH group and the carbonyl oxygen atom of the -COOCH3 group cooperated with Ag+ throμgh electrostatic gravitational interaction. This method was used to establish the detection of Ag+ in food in which the detection limit of L5 for Ag+ was derived as 0.13 μmol/L, and the silver ions in wolfberry, milk powder,wheat flour, tea leaf and soybean were accurately detected. This method can be used to quantify Ag+ content in actual samples accurately and efficiently.