Aimed at the blade chordwise pendulum resonant loading system, springdamping model of the system was established. By using the Lagrange equations the differential equations of motion of the system were derived. The blade chordwise fatigue loading resonance energy was analyzed, the system dynamics analysis and parameter matching were carried out, and test on the fatigue loading experimental device was completed. The experimental results show that when the deviation between the driving frequency and the natural frequency of the blades is rather large, acute fluctuation of its viberation amplitute is then occurred, when the deviaton is quite small, the amplitude is tended to be stable. It provides a practical reference and theretical basis for the application of fatigue loading system.