High-level (HL) and low-level (LL) competitive aerobics athletes demonstrate different landing patterns during rotational jump landings, resulting in differing risks of lower limb injuries. This research aimed to investigate biomechanical differences between different levels of competitive aerobics athletes during rotational jump landings. The subjects included 15 male HL athletes and 15 LL athletes. This study captured kinematics, kinetics, muscle activation, and muscle force data, calculating joint stiffness, energy dissipation, anterior tibial shear force (ATSF), and patellofemoral joint contact force (PTF). LL athletes demonstrated significantly greater ankle dorsiflexion, inversion, and internal rotation angles; knee abduction angle and moment, internal rotation angle and moment; and smaller ankle plantarflexion moment and knee flexion angle. They also showed lower calf muscle coactivation, PTF, joint stiffness at the knee and hip, and the energy dissipation of the ankle and lower limb; greater thigh muscle coactivation and ATSF. The results show that LL athletes exhibit poorer stability at the ankle and knee joints, with a higher risk of anterior cruciate ligament (ACL) and ankle inversion injuries during rotational jump landings. To lower these risks, LL athletes should increase the flexion angle of the knee, hip, and ankle plantarflexion during landing.