Traditional lap-slip mechanics models have not taken into account the important factor of steel bar spacing, leading to inaccurate predictions of steel bar overlapping performance. To address this, a tensile test considering factors such as steel bar spacing was conducted, and the influence of spacing on overlapping performance was investigated. A mechanical model considering steel bar spacing was developed and validated for accuracy and generalization. The results demonstrate that the proposed model considering steel bar spacing improves accuracy by nearly 50% compared to traditional lap-slip models. For ECC-steel overlapping members, the correlation coefficient between the model and experimental results exceeds 0.95. The model shows good generalization, effectively predicting the overla-pping performance of steel bars in high-performance concrete and ordinary concrete, and is suitable for predicting the overlapping performance of reinforced concrete overlapping members.