To study the fluid flow and heat transfer condition outside the hybrid smooth and spirally corrugated tube at Re=1.0×104~3.5×104 and provide reference for structure design optimization, the Realizable k-ε turbulence model was used to simulate the convective heat transfer process on the shell-side under constant wall temperature, and the effects of geometrical parameters including pitch p and corrugation depth e on the flow field, the temperature distribution and other turbulent statistics, were explored. Results indicate that the swirl flow out of the hybrid smooth and spirally corrugated tube is less violent than that in the tube-side; the secondary flow exists in the entire domain and the heat transfer performance is enhanced consequently, resulting in the increase of pressure loss simul-taneously; the hybrid smooth and spirally corrugated tube with pitch ratio p/D=3.50 has a superior thermal-hydraulic performance; the tube with corrugation depth ratio e/D=0.22 holds the highest local Nusselt number and the largest pressure drop.