The　heat　transfer　performances　of　the　micro-jets　array　impingement　were　studied　by　numerical　simulations.　After　validating　the　model,　the　effects　of　rectangular　pulses　were　analyzed　on　heat　transfer　characteristics　by　adjusting　the　pulse　parameters.　Then,　some　reasons　for　using　rectangular　pulse　jets　to　enhance　the　heat　transfer　were　discussed　by　flow　field　analysis.　All　of　the　simulations　show　that,　if　the　duty　ratio　of　the　pulses　is　0.5,　the　heat　transfer　characteristics　of　the　micro-jet　array　will　be　effectively　enhanced　when　the　mean-time　Reynolds　number　is　increasing.　The　enhancement　of　heat　transfer　by　the　adjustment　of　frequency　is　highly　dependent　on　the　flow　regime　of　the　jets.　In　the　proper　frequency　band,　the　heat　transfer　coefficient　of　turbulence　flow　can　increase　by　20%,　and　the　coefficient　of　laminar　flow　can　increase　by　7.5%.　Under　rational　conditions,　rectangular　pulses　jets　can　strengthen　the　impact　effects　and　the　disturbance　of　vortex　in　the　cavity,　therefore,　the　micro-jet　array　can　obtain　better　heat　transfer　performance.　©　2018,　Editorial　Office　of　Journal　of　Vibration　and　Shock.　All　right　reserved.