本文对矩形、正T形、倒T形截面的38根预应力试验梁进行了施工阶段预拉区非预应力筋的应力和混凝土开裂情况的现场测定.并对预应力受弯构件在短期荷载作用下,预拉区裂缝对正截面的强度、抗裂度和刚度的影响进行了试验研究.本文还对预压阶段裂缝截面考虑材料非线性进行了理论分析,从而为修订规范提供依据. In this paper, 38 prestressed test beams with rectangular, T-shaped and inverted T-shaped cross-sections were measured on site for prestressed non-prestressed tendons and for concrete cracking in prestressed areas, The effect of cracks in pre-tension zone on the strength, crack resistance and stiffness of the cross-section was studied.The theoretical analysis of the material nonlinearity in the pre-compression fracture section was also carried out, which provided the basis for the revision of the code.