To explore the mechanical properties of integral abutment-RC pile-soil structure, we designed and prefabricated four integral abutment-RC pile models with different pile foundation reinforcement ratios and cross-section shapes taking an integral abutment bridge in China as background. The quasi-static test of integral abutment-RC pile-soil interaction under low cyclic loading was carried out. The effects of reinforcement ratio and cross-section shape of RC pile on the mechanical properties of abutment-RC pile-soil system were mainly studied, and the soil resistance behind abutment, the soil resistance beside pile, and the distribution of pile strain and bending moment were analyzed. Results show that under the action of cyclic displacement of abutment, the distribution of soil resistance near the abutment back along the height direction changed from “triangular” distribution to “parabolic” distribution, and that away from the back of the abutment was basically in “triangular” distribution. The resistance of soil behind abutment was affected by the reinforcement ratio and section shape of RC pile, so it is necessary to increase the reinforcement ratio of RC pile or use rectangular section to improve the integrity of integral abutment-RC pile-soil system. The cumulative deformation of pile affected the distribution of soil resistance on the sides of pile, which reduced the soil resistance behind pile and increased the soil resistance in front of pile. The specimens with larger reinforcement ratio or rectangular cross-sectional RC piles were less affected by the cumulative deformation, and the integrity of abutment-pile foundation-soil structure was better. When the integral abutment-RC pile structure moved to the river span side, the distribution of pile strain and bending moment was consistent with that of traditional pile foundation. When moving to the riverbank, the maximum strain and bending moment of pile appeared at the joint between the bottom of abutment and the top of pile. Increasing the reinforcement ratio of RC pile or adopting rectangular cross-sectional RC pile can effectively reduce the strain and bending moment of pile body and improve the mechanical performance of RC pile foundation.