Purpose <p>The clearance change of the blades during actual operation will change the work done by the incoming flow on the blade surface, affecting its flutter characteristics. This study aims to explore the influence laws of the clearance variation on the blade flutter and provide reliable data to prevent the blade from failing due to flutter.</p> Method <p>A numerical model for calculating the aerodynamic damping ratio of a dual-channel axial compressor rotor is established using phase-delayed periodic boundary conditions. The energy method is adopted to evaluate the influence of the tip clearance variation on the aeroelastic stability of the blades.</p> Results <p>The effect of clearance variation on aerodynamic damping is considered for different inter-blade phase angles and modes, and the distribution of aerodynamic work on the blade surface under various clearance conditions is analyzed.</p> Conclusion <p>Phase angle: Under the first three-order modes, there are certain differences in the variation trends of the aerodynamic damping ratio with the inter-blade phase angle. However, the overall variation trend is that it gradually increases as the phase angle increases. Mode: In the first-order bending and first-order torsional modes, when the tip clearance increases, the aerodynamic damping ratio generally decreases gradually, and the aeroelastic stability decreases. However, in the bending-torsion coupling mode, in the range of IBPA from -180° to -80°, increasing or decreasing the tip clearance will basically increase the aerodynamic damping ratio. In the range of IBPA from -80° to 80°, increasing the tip clearance will increase the aerodynamic damping ratio, enhancing the aeroelastic stability of the blades. In the range of IBPA from 80° to 150°, increasing the tip clearance will gradually decrease the aerodynamic damping ratio, reducing the aeroelastic stability of the blades. Aerodynamic work: In the first-order bending mode, reducing the tip clearance makes the growth rate of the intensity and scope of the positive aerodynamic work on the blade surface faster than that of the negative aerodynamic work, accelerating the risk of flutter occurrence. In the first-order torsional and bending-torsion coupling modes, when the clearance is reduced from the designed clearance to 0.5 times the designed clearance, the growth rate of the intensity and scope of the negative aerodynamic work on the blade surface is faster than that of the positive aerodynamic work, suppressing the occurrence of flutter.</p>