The invention provides a synergistic composition containing fluensulfone, which includes an active component A and an active component B; the active component A is the fluensulfone; the active component B is one or more selected from: amisulbrom, isotianil, fluindapyr, isopyrazam, fenpyrazamine, inpyrfluxam, mandestrobin, copper octanoate, dipymetitrone, fenpicoxamid, spinetoram, metaflumizone, sulfoxaflor, dicloromezotiaz, lepimectin and bistrifluron; the synergistic composition also includes available additives in precipitate preparation processing to produce common precipitate preparations,which are applied to prevention and treatment on plant diseases and pests.