The normal content of trace element lead in human body should not exceed 100μg/l, and children should not exceed 60μg/l. If the lead content in human body exceeds this normal value, it is called lead poisoning, which will cause serious harm to human body. The body will enter the human blood circulation through the digestive and respiratory tracts after being exposed to lead from outside, and if it is not metabolized in time, it will cause damage to the nervous system. High lead content in children’s body will lead to slow reaction, low memory and even dementia, and high lead content in pregnant women will lead to fetal malformation or miscarriage. Lead is a trace element in human body, and the effect is not obvious within the normal range. Eating more duck blood and vegetables can help to discharge lead from the body and avoid the harm caused by high lead content. In daily life, we should pay attention to food safety, eat less canned products and avoid inhaling car exhaust.