Abstract: A field efficacy trial on combined use of different concentration of biogas slurry with pesticide to control diseases in Cuiguan pear was conducted. The results showed that better drug efficacy were shown by adding 25% or 50% concentrations of biogas slurry to pesticide solution, compared to pesticide solution only, the diseased leaf rate and diseased fruit rate were also decreased. It illustrated that the combined application of 25%-50% concentrations of biogas slurry with pesticide could improve the efficacy of pesticide in the disease control for Cuiguan pear.