Abstract: Basalt fiber reinforced polymer (BFRP) bars are a new material alternative steel reinforcement in marine construction, attracting widespread attention in the engineering circles. In this study, four-point bending tests were performed on 18 concrete beams reinforced with BFRP and 2 conventional reinforced concrete beams. The study examined the impact of reinforcement ratio, concrete strength, BFRP bar diameter, and anchorage mode on the bending performance of structures. Load-displacement curves and failure modes of BFRP reinforced concrete beams were recorded. Key parameters, including cracking load, ultimate bending moment, and mid-span displacement, were analyzed to quantitatively assess the ultimate bearing capacity of the beams. Based on the experimental results of this paper and relevant data from 89 FRP reinforced concrete beams reported by domestic and international researchers, a calculation method for flexural capacity was proposed. The reliability and predictive accuracy of this method have been validated through experiments. The results indicate that bond strength is an important factor affecting the ultimate load-bearing capacity of BFRP reinforced concrete beams. Both the bond strength and the ultimate load-bearing capacity of the beams would be enhanced certainly by increasing the reinforcement ratio of BFRP bar. Furthermore, the bond strength and crack resistance are significantly influenced by the anchorage method, but the ultimate load capacity is affected to a minor extent. Considering the contribution of the upper longitudinal reinforcement in calculations leads to a more accurate representation of the actual bending capacity of BFRP reinforced concrete beams. By introducing a dimensionless parameter μ_p, this study establishes a formula to calculate the equivalent compressive zone height x and μ_p, for different failure zones. Theoretical calculations indicate that the predicted bending moment values in the transition zone are larger than that achieved by the current standards code, while those in the compression zone are more conservative. The proposed prediction formula is straightforward and physically meaningful, demonstrating average error of 8.6% and a variance of 0.062 when compared to experimental data, indicating good agreement with the experimental results. This method provides an effective approach for evaluating the bending capacity of BFRP reinforced concrete beams.