Abstract: In this study,a fan-shaped cavity structure was added to the micro-channel to study its effect on the flow and heat transfer in the micro-channel.The effects of structural changes on the flow and heat transfer characteristics of fanshaped cavity micro-channels with different size parameters are discussed.The synergy between velocity field and pressure field as well as between velocity field and temperature field is analyzed in the direction of field synergy theory.Finally,the comprehensive performance of each micro-channel is elaborated through entropy generation analysis.The results show that the synergistic angle between velocity vector and pressure gradient in the micro-channel increases,the resistance loss of the micro-channel increases,and the synergistic effect of the field decreases;while the synergistic angle between velocity vector and temperature gradient decreases generally,the heat transfer is promoted by disturbance and secondary flow,and the synergistic effect of the field increases;and the field synergistic number is introduced to express the velocity field and temperature field.The synergistic effect of MCC-0.5-1.5 field was the largest,averaging 0.002 94.Entropy production analysis shows that the fan-shaped cavity structure reduces the irreversible loss of micro-channels,and the increase of MCC-0.5-1.5 is the smallest,averaging 0.74.