Abstract: In order to study the difference in flexural performance of continuous composite box girder with corrugated steel webs between under monolithic cast-in-place construction technology and under segmental precast assembled construction technology, a precast segmental continuous box girder with corrugated steel webs and variable cross-section and a monolithic continuous box girder with corrugated steel webs of the same size were tested. The influence of the existence of joints on the strain distribution, the change of load-deflection and prestress increment on different sections of precast segmental continuous girder with corrugated steel webs was analyzed. The failure modes of the two girders were analyzed. The results show that the existence of joints has little influence on the stiffness of the test girder at the initial loading stage, and the strain and deformation of the two girders are similar. The concrete strain between the joints of the segmental assembled girder after cracking is relatively small compared with the monolithic cast girder, but the concrete strain at the joints is relatively large. The plastic deformation of the joints makes the internal force redistribution more obvious. The cracks in the monolithic cast girder are typical bending cracks. The number of cracks in segmental assembled girder is relatively small in the whole process and the distribution range of cracks is mainly in the joints on both sides of segments. In the plastic stage, the deformation of segmental girder mainly occurs at the joints, and the deformation of beam body is relatively large. The deflection of the side span is smaller than that of the middle span. The prestressed reinforcement of the segmental assembled girder plays a greater role than the monolithic cast girder, and the growth rate of the stress is faster. The change of the effective height of the segmental assembled girder is less than that of the monolithic cast girder. The calculation formula of bending capacity of precast segmental assembled continuous box girder with corrugated steel webs is proposed, and the calculated values of the formula are in good agreement with the experimental results.