Abstract: The effects of ecological control on poplar longicorn with composite management system and released several natural enemies was studied. The results showed that the model of composite management and released Scleroderma guani Xiao el Wa is tire best for control effect. "The infection rate, the average population density and relative population density decreased by 66.0%, 98.3% and 41.5% respectively. The control effect of releasing S. guani with Beauveria bassiana had significantly improved. In addition, S. guani could form field population in the poplar forest after it was released. Poplar longicorn was also sustained. Afforesting a large area of composite management system in poplar planting area was recommended. Protecting natural enemies and releasing S. guani would play an important role in ecological control poplar trunk longicorn.