Multi-MW wind power converters are widely applied in wind power field. Converters are paralleled to expand converter's capacity. Due to the wind power fluctuation, IGBT's power handling ability together with its drive power is fluctuating largely and rapidly, which will cause a large temperature variation, affecting the reliability and lifetime of power semiconductors. In this paper, the thermal smooth control for DC-BUS connected parallel wind power converter is proposed to improve the converter's reliability. In the proposed thermal smooth control, orthogonal circulating current is introduced to smooth the thermal stresses of IGBTs. Therefore, a balanced thermal can improve IGBT's reliability, which can improve the wind power converter's reliability. Finally, MATLAB/PLECS simulation is carried out to validate the proposed thermal control. The simulation results indicate the feasibility and advantage of the proposed thermal smooth control.