The enhancement of convective heat transfer in the tube will further improve the comprehensive performance of heat exchanger and make it suitable for higher heat flux conditions. Swallow tail longitudinal swirl generators (STLSGs), a novel type of tube inserts, was proposed in this paper and its characteristics of heat transfer and flow were numerically investigated under laminar flow. The effect of inclined angle (θ₁), wing angle (θ₂), tail angle (θ₃) and pitch (P) on thermal hydraulic performance was explored. The results showed that the enhanced tube with STLSGs obtained excellent heat transfer augmentation, and the variation ranges of Nu/Nu₀ was 4.10-7.76. There were two main explanations: The first one was that the multi-vortexes longitudinal swirl flow would be formed by STLSGs in the tube, which achieved the effect of mixing flow and uniformity of temperature. The another one was that the fluid was guided by STLSGs to scour the wall, and the boundary layer was in a state of continuous destruction and reconstruction, which increased the temperature gradient near the wall. Meanwhile, the design of tail angle would effectively reduce the momentum loss caused by the fluid impact on the wall, so as to reduce the flow power consumption. This study found that the heat dissipation of the enhanced tube was decreased 43.2-88.8% compared with the smooth tube and the efficiency of heat transfer was greater than 97.4%. Dissipation minimization principle was applied to optimize STLSGs by coupling artificial neural networks and genetic algorithms. The geometric parameter of the compromised point on the Pareto front obtained after optimization were θ₁=30.0°, θ₂=5.8°, θ₁=98.7°, P=52.4 mm, and its efficiency evaluation criterion (EEC) was 1.25, achieving the excellent overall heat transfer performance. The present work provided new effective evaluation indexes, heat dissipation and power dissipation, for design and optimization of heat transfer augmentation.