Abstract: The three-point bending tests were conducted for the study of bending damage and acoustic emission response characteristics of wind turbine blade composite material with fiber fracture defect. Experimental results showed that the load-deflection curve of composite specimen was linear approximately, and the strength of composite specimen decreased sharply by the fiber fracture defect in the surface 20 plies. Comparing the strength and stiffness between specimen with fiber fracture defect in the middle 20 plies and specimen free of defects, a few differences were found. For the fiber fracture defect, failure mode of wind turbine blade composite material was changed. It was also found that the acoustic emission characteristics such as amplitude, energy, impact, rise time, duration, count and other parameters in bend tests were useful for monitoring the damage development and failure of the specimen.