At present,the large-span porous steel corrugated plate arch culvert reinforced with composite beams of concrete-steel corrugated plate(referred to as"concrete ring")has been preliminarily applied in actual projects.However,the force and deformation characteristics in the construction process have not been studied in depth.This paper combines the in-situ test of a 9 m span steel corrugated plate arch culvert with 4 holes to monitor the mechanical behaviour of the concrete ring and the steel corrugated plate,establish a refined finite element model,compare the force and deformation characteristics of the structure in different sections,and study the influence of the concrete ring on the structure.The results show that:1)different arch spans and the presence or absence of the concrete ring have little effect on the deformation of arch culverts;2)in the backfilling of the arch,the stress of the steel corrugated plate and rebar of the side span are greater than the corresponding position of the middle span,and the maximum difference is 47.26 MPa and 49.75 MPa,respectively;3)the concrete ring can significantly reduce the stress of the steel corrugated plate,which is about 10%of its design strength.