根据预应力混凝土箱梁在弯剪扭共同作用下的抗扭特性，以修正斜压场理论和薄壁管理论为基础，提出了适用于弯剪扭共同作用下预应力混凝土箱梁的抗扭极限强度计算的理论模型．所建立的计算公式不仅理论基础强、简洁易行，而且与所验证的２４根模型构件的试验结果符合良好． Based on the torsional behavior of prestressed concrete box girder under the combined action of bending, shearing and torsion, based on the modified oblique pressure field theory and thin wall management theory, the torsion resistance of prestressed concrete box girder under the combined action of bending, shearing and torsion was proposed. Theoretical model of ultimate strength calculation. The established formula is not only theoretically strong, simple and easy to implement, but also in good agreement with the experimental results of the 24 model components verified.