Schistosoma harms are divided into the following aspects: 1. intermediate hosts: invade into the nail snail, affecting the metabolism, growth, reproduction as well as survival of the snail, the life span of infected schistosomes is shorter, and the mortality rate of infected nail snails usually increases; 2. end hosts human: human parasites have damage to all human bodies, such as seizure of nutrients, mechanical damage, toxin effects, immune metabolic reactions, etc. Schistosomiasis infects people with schistosomiasis, and schistosomiasis affects human life, growth, production, life, fertility, birth, interest and life span. Although acute and chronic schistosomiasis is hardly fatal, late stage schistosomiasis can seriously affect human life expectancy and seriously damage human body, resulting in long duration of illness, poor treatment, restricted activities, reduced income, high medical costs, poverty due to illness and return to poverty due to illness, etc.; 3. Mammals: As damaged as humans, schistosomes are harmful to nature, especially Japanese schistosomiasis, which is more pathogenic than other kinds of schistosomiasis Schistosomiasis japonica is more destructive and more harmful to human beings, especially because of the large amount of eggs produced and the fact that eggs are the main cause of the disease.