Effects of copper ion stress on the growth and physiological metabolism of peanut seedlings were studied by treating peanut seedlings of Silihong peanut in pot with different concentrations of copper sulfate solution in order to provide theoretical reference for further understanding the toxic mechanism of heavy metals on peanut growth.The results showed that with the increase of copper ion concentration, the fresh weight and lateral root length of peanut seedlings continued to decrease; plant height, main root length, SOD, POD and CAT activities in leaves, proline content in stems and leaves, chlorophyll A content, chlorophyll B content and carotenoid content all increased first and then decreased, and there was a peak in MDA content and relative electricity content in stems and leaves.When the concentration of copper ion was 100μmol/L, peanut showed stress reaction, and when the concentration reached 1 000μmol/L, peanut growth was harmed.