In order to suppress the second harmonic flapwise loads of stiff in-plane rotor blades,the dynamic absorbers need to be embedded in the blade cavity in the blade flapwise direction. To investigate the effect of the embedded absorber in the flapwise direction of the rotor blade on the second harmonic moment, the coupled dynamic model of rotor blade and flapwise dynamic absorber is established. The differential equations of motion of the rotor blade coupling system with flapwise absorber are derived by using the Lagrange equation.The comparison of load suppression effect of fluidelastic absorber and elastic absorber in blade flapwise direction on blade root is conducted.And the structural parameters affecting the absorber performance and the dynamic characteristics of flapwise absorber in rotating state are analyzed. The study shows that the natural frequency of flapwise absorber is not changed when it is rotating or not.Both fluidlastic absorber and elastic absorber can achieve good effect on reducing lower harmonic loads in the direction of flapwise of the blade, but the stroke of fluidlastic absorber is significantly less than that of the elastic absorber.