As the development of integrated circuit (IC) devices continuously towards high density and high integration, microchannel cooling technology is becoming an inevitable option for solving heat dissipation of high power density. This work investigated the field synergy and heat transfer performance of the microchannels with three different internal spoiler cavities configurations using a three-dimension numerical simulation of conjugate heat transfer model. The analysis of temperature field, flow field, field synergy angle and thermal characteristics were presented to discuss the heat transfer enhancement mechanism. It was found that the field synergy angle and Nu number have a good consistency on evaluating the heat transfer enhancement in terms of the internal spoiler cavities in the microchannel. Additionally, the field synergy effect in the microchannels was optimal when the internal spoiler cavities of the microchannels were configured in form of front-loose-back-compact (FLBC) under laminar flow, which could achieve the optimization of heat dissipation performance in a limited space without any pressure drop. (C) 2018 Elsevier Ltd. All rights reserved.