Abstract: The three-dimensional numerical analysis model of an interlaced scallop damper seal was established. The dynamic characteristics in the axial direction was studied. Effects of the interlaced angle (α=0°, 11.25°, 22.5°, 33.75°) and seal cavity depth (h=2.8 mm, 3.3 mm, 3.8 mm, 4.3 mm) on the dynamic characteristics of the scallop damper seal were analyzed based on dynamic mesh method and multi-frequencies elliptic whirling model. Results showed that the upstream seal cavity (C1~C4) had a large positive direct stiffness and effective damping, which showed a relatively greater contribution to suppress the rotor whirling and improved the system stability. Compared with the parallel structure (α=0°), the interlaced scallop damper seal had lower circumferential velocity, higher turbulence dissipation, better system stability, and lower seal leakage flow rate. When the interlaced angle was 33.75°, the effective damping was about 111% to 121% of that at 0°. The leakage flow rate for an interlaced angle of 22.5° was about 2.11% lower than that at 0°. The effective damping increased with decreasing seal cavity depth. The effective damping of the seal with cavity depth of 2.8 mm was 146% to 211% that of 4.3 mm. The leakage flow rate of the scallop damper seal decreased with increasing seal cavity depth. The leakage flow rate for the seal cavity depth of 4.3 mm was reduced by about 3.73% compared with that of 2.8 mm.