To address the cracking problem of the concrete bottom slab in traditional concrete trough beams, a composite trough beam with corrugated steel webs wrapped with steel plate (CTBCS) was proposed based on the structural advantages of corrugated steel webs. To investigate the flexural behavior of CTBCS, a scaled test beam was designed and fabricated for static loading tests, and its failure mode, load-displacement curve, strain distribution, and flexural capacity were analyzed. A quarter-symmetry model of the test beam was established in ABAQUS for nonlinear finite element analysis. The flexural capacity of CTBCS was derived theoretically, and the experimental, numerical, and theoretical results were compared. The results show good agreement among the three. CTBCS exhibits plastic failure characteristics and good ductility under bending loads. The wrapped steel plate significantly improves the flexural capacity of the structure and reduces the lateral displacement, crack width, and number of cracks. The flexural capacity of CTBCS increases linearly with the increase in the thickness of the wrapped steel plate, whereas the growth rate gradually decreases. CTBCS can effectively overcome the mechanical deficiencies of traditional concrete trough beams, and the research results provide an important scientific basis for the study of the mechanical properties and further application of composite trough beams.