Abstract: The rubber impellers of flexible impeller pumps are prone to fatigue failure due to local stress concentration during cyclic bending deformation, and the material properties of rubber exert a remarkable influence on its mechanical behavior. A single-blade finite element model was built based on LS-DYNA to simulate the complete operational cycle of the impellers within the stator cavity from installation and bending to elastic recovery, aiming to investigate the stress concentration characteristics and their correlation with materials. The stress responses of four materials (chloroprene rubber, nitrile butadiene rubber, polyurethane, and natural rubber) were systematically compared. Results reveal that the central regions near the edges of the front working surface and the midsection of the rear working surface are typical high-stress zones with peak equivalent stress of 1.48 MPa, making them susceptible to crack initiation. Different elastic materials have a significant influence on stress concentration characteristics. Hard rubbers like polyurethane generate contact stress up to 2.47 MPa due to strong conformity with the stator, ensuring excellent sealing performance but intensifying local stress concentration. In contrast, soft rubbers such as natural rubber have a contact stress of only 0.03 MPa, effectively reducing stress levels but compromising sealing due to poor conformity.