With a new two-layer algebraic turbulence model, the thin-layer Navier-Stokes equations are employed to simulate a transonic flow past a SOCBT projectile with porous surface at 10° angle of attack. The porous surface at the boattail of a SOCBT projectile has caused effectively the original normal shock to become a weaker lambda shock, resulting in a drag reduction and a lift increase. In the present study, a total drag reduction about 9.97% and a lift increase of 11.86% can be achieved.