Abstract: Double steel plate-concrete composite structures are widely used in high-rise buildings, in immersed tube tunnels, in bridge engineering and protective structures. The synergy between steel plates and concrete results in superior structural performance. Self-compacting concrete, due to its excellent flowability, is often used in these structures. However, the interface between steel plates and concrete can easily develop issues such as poor compaction and void formation, affecting the connection and synergy between steel plates and concrete. To address this issue, a numerical model for self-compacting concrete pouring is established by the grounds of the VOF method, simulating the flow behavior of concrete within the formwork and predicting void formation. The feasibility of the VOF method is verified through numerical simulations of slump expansion tests and of L-shaped box tests, and the accuracy is demonstrated through numerical simulation of compartmental pouring tests. Several compartment models are set up based on different influencing factors to investigate their impact on concrete void formation and to identify key influencing factors. The research results show that: the fluid model established can effectively simulate the rheological behavior of concrete; the number of vent holes, spacing of connecting holes, studs, and pouring speed significantly affect the void formation during concrete pouring; the number of vent holes should be appropriately increased, the spacing of connecting holes should be reduced, and the number of bolts should be decreased; and the pouring speed of concrete should be controlled to be neither too large nor too small.