<p>The steel-shell concrete immersed tube (SSIT) with the self-compacting concrete (SCC) has been applied in the Shenzhen–Zhongshan Link, and the SSIT is prone to the void defect during the concrete pouring process. This work aims to study the flow behavior of the SCC and investigate the generation and distribution of the void defect in the SSIT, and the computational fluid dynamics (CFD) models are adopted to solve the above problems. To verify the CFD models, the slump test, L-box test, and field test based on Ok. the impact image method are carried out. The effects of the connecting hole spacing, the exhaust hole number, the exhaust hole position and the pouring speed on the flow behavior and the void defects distribution are quantitatively compared. According to the comparison results, the standard compartment with 300 mm connecting hole spacing and 10 exhaust holes is the optimal compartment structure design, and the concrete pouring speed of 15 m³/h is the optimal construction method. This work demonstrates that the CFD model offers a useful way to evaluate the generation and distribution features of the void defects for the steel–concrete-steel structure.</p>