In the past, prestressed carbon fiber plate reinforcement bending tests were mostly based on the "first load" of the structure. In this paper, prestressed carbon fiber plate reinforcement "second load" of the reinforced concrete bending structure is studied experimentally from the actual situation that the structure is mostly "second load" in the reinforcement engineering. On the basis of the special anchorage for prestressed carbon fiber plate developed by Liuzhou Overwem Machinery Co., LTD., the author completed the model test of the flexural members of 2 test beams reinforced by prestressed carbon fiber plate and 1 test beam reinforced by non-prestressed carbon fiber plate. The mechanical properties of test beams reinforced by prestressed carbon fiber plates are studied. The effects of prestressed carbon fiber reinforcement on the bearing capacity, deformation, application efficiency and ductility of the specimens were studied. The test results show that the prestressed carbon fiber plate reinforcement can significantly increase the cracking and yield load of the flexural members, reduce the deformation of the members during the use stage, make full use of the properties of carbon fiber materials, and strengthen the design against the decreasing trend of ductility.