Abstract: Focusing on the environmental risk issues of heavy metals contained in discarded printed circuit boards（PCBs），the content of eight main toxic and harmful metals in PCBs of automobiles，televisions，and routers was analyzed. Furthermore，the occurrence forms and leaching characteristics of metals were analyzed and evaluated. The experimental results showed that the content of various metal substances in the circuit board varied greatly within the experimental range，with the content of Fe，Cu，Pb，Cr，Sb，Sn，Cd，and As ranging from 0. 015 - 294. 9 mg/g. Although the content of Cd and As was relatively low，their toxicity was relatively high. The main occurrence form of Cu，As，Sn，and Sb in circuit boards was a residual state，with a low ecological risk level. Pb mainly existed in acidsoluble and oxidized states，while Fe，Cr，and Cd existed in four forms：exchangeable and weakly acid-soluble，reducible，oxidizable，and residue states，with a high ecological risk level. Cd，Cr，Cu，As，Fe，Sb，and Sn were leached under environmental conditions simulating neutral and acidic rainfall and landfill leachate. The leaching rate of Pb was high in the simulated landfill leachate leaching experiment. The leaching rate of As was higher in simulated neutral and acidic rainfall. The concentrations of Cd，Cr，Cu，As，Fe，Sb，and Sn in the leaching solution under various environmental conditions exceeded the limit of general chemical indexes of rank Ⅲ of GB/T 14848—2017.

Key words: waste circuit board, heavy metals, occurrence form, leaching characteristics