In view of the limitations of traditional nondestructive testing methods for wind turbine blades, this paper proposes an electromagnetic ultrasonic testing technology. The technology has the advantages of non-contact, no coupling agent and strong environmental adaptability. In this method, according to the principle of electromagnetic ultrasonic detection, the research objects are 13mm non-destructive blades and defective blades with bubbles, inclusions and degumming. Firstly, the electromagnetic ultrasonic transducer with square permanent magnet and track coil is built by using COMSOL. Then, the stress nephograms and waveforms of various blade models are obtained through the electromagnetic ultrasonic transducer. Finally, the defect waveform is compared with non-destructive waveform to analyze the defect condition of the blade. The results show that the simulation model can detect three kinds of defects inside the blade, which proves that the relationship between the defect echo and the defect radius is basically linear, and the relationship between the bottom wave and the defect radius is negative, and verifies the feasibility of the electromagnetic ultrasonic finite element simulation analysis of the wind turbine defects.