Based on the characteristics of the colorimetric chemosensor，the exchangeable Cu2+ in the soil was detected through the qualitative visual change of the solution color and the quantitative visualization of UV-Vis spectrophotometry.The 2～50 mmol/L Cu(NO3)2 solution was mixed into montmorillonite and kaolin，and contaminated soil samples were collected from copper mines.The exchangeable Cu2+ was extracted using a standard CaCl2 cation exchange approach，and the Cu2+ concentration in the resulting solutions was determined by UV-Vis spectrophotometry using a chemosensor，and it was compared with traditional inductively coupled plasma mass spectrometry (ICP-MS) analysis.Analytical results showed that the lowest detectable concentration in the contaminated soil was 0.030 mmol/L，and the color change of the solution could be discerned by the naked eye and be visualized.The quantitative analysis method of exchangeable Cu2+ based on CaCl2 extracted in the soil system using colorimetric chemical sensor is proposed for the first time，which can provide a certain theoretical basis for the visual and quantitative detection of harmful metal elements in the soil.