To improve overall thermal performance of interrupted microchannel heat sink, the forward and backward wedged ribs were introduced in transverse zones of interrupted microchannel. Numerical investigation on the flow and heat transfer characteristics of these microchannels was conducted. The obtained results were compared with those of the smooth microchannel (PMC) and the interrupted microchannel (IMC). The comparison results show that the pressure drop, heat transfer coefficient and overall thermal enhancement factor of the interrupted microchannel with backward wedged ribs (IMC-BW) are higher than those of other microchannels at most of operating conditions. In addition, at the whole of inlet velocity studied, the pressure drop and heat transfer coefficient of IMC-BW channel are 11.96% and 32.74% higher in average than those of PMC channel, respectively, as well as 18.76% and 24.57% higher in average than those of IMC channel, respectively. The overall thermal enhancement factor of IMC-BW channel ranges from 1.20 to 1.34, and is 17.64% higher in average than that of IMC channel.