Offset strip fin has higher heat transfer characteristics than plain fin by disturbing development of boundary layers. Because of its good thermal performance, offset strip fin is applied to various fields such as HVAC system, Fuel Cell. However, offset strip fin has the disadvantage that the mixing of the flow is insufficient, because the flow only flows linearly. So, we devised a new concept of offset strip fin with a bent shape and investigated heat transfer and pressure drop characteristics with variation of bending angle. The research was conducted numerically. Numerical simulation is conducted by ANSYS CFX19.2 using RANS model and we used naphthalene sublimation technique as experimental method for turbulence model validation. The research was conducted with varying angle of bend from 0 to 40 degree. As a result, even if the angle of the bend is small, the heat transfer is higher than that of the conventional offset strip fin, and it has the maximum heat transfer value in the case of 40 degree. The reason is that the flow passes wavy as the fin has a curve, which makes more secondary flow and stronger. Friction Factor also increased as the bending angle increased. Case of 30 degree showed the highest thermal performance factor.