Fluent software was used to study the effects of four different types of rectangular wings on the laminar flow and heat transfer of the fluid in the heat exchanger microchannel when the Reynolds number was 200 to 1100,and compared with the smooth microchannel. The results showed that the best arrangement was that the two pairs of rectangular wings were bracketed,and when Re = 1100,the Nu increased 39. 7% over the smooth microchannel. Under this configuration,the regularity of the effect of rectangular wings with different spacing on the laminar flow and heat transfer of the fluid was： PEC increased first and then decreased with increasing spacing. The optimal spacing was g_1= g_2= 4 H,and the maximum PEC was 0. 62.