Abstract: This study investigates the dynamics characteristics of rotor blades with cracks under aerodynamic excitation. Based on the one-way fluid-structure coupling computational method, the aerodynamic forces and structural dynamic characteristics of high-speed blades with cracks under aerodynamic excitation are studied. The standard k-ε turbulence model is used to perform three-dimensional unsteady flow calculations for cracked blades at different rotational speeds, obtaining the aerodynamic forces on the blade surfaces and the static pressure variations at key points on the surfaces of the cracked blades. The wet modal analysis method is used to study the dynamics characteristics of the cracked blades under aerodynamic excitation. The research results show that under stable rotational speed, the distribution of aerodynamic forces on the windward side of the blade indicates that the closer the position is to the leading edge of the blade, the greater the aerodynamic force; while on the leeward side of the blade, the aerodynamic forces decrease as the positions get closer to the leading edge. The magnitude of the aerodynamic forces does not exhibit a clear relationship with the position along the blade length. At different rotational speeds, the velocities at which the aerodynamic forces at monitoring points reach the steady-state range increase with the rotational speed. Under the aerodynamic excitation, the modal frequencies of the cracked blades increase with the increase of rotational speed, and at the same rotational speed, the modal frequencies of the cracked blades are lower than those of the intact blades. The research results provide reference significance for the aerodynamic optimization design and damage detection of rotor blades.