The natural starch has the advantages of low toxicity, easy to be degraded, and can be recycled. It has the ability of capturing heavy metal after multi modification.Using quaternary ammonium type etherification agent, phosphate and urea were used to modify starch molecules, and finally, a variety of charge distribution of starch molecular modified products were obtained.The microstructure, properties and mechanism of starch based collector were studied by means of infrared spectroscopy, solid state nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) and trapping efficiency.The results show that: the starch molecules into the cationic quaternary ammonium groups, anionic phosphate groups and nonionic amide groups; the specific surface area increasesis conducive to trapping heavy metal ions. The removal rate of copper, lead, cadmium and nickel ions in 30mg/L mixed solution was 97.80%, 99.83%, 99.23%, 99.53%, respectively, which were up to the national emission standard. The trapping process is in accordance with the pseudo two stage adsorption model, which is controlled by the combination of electric neutralization reaction and micropore adsorption.