The research results of dry technique on the etch pattern of forming micro-mesa arrays for HgCdTe IRFPAs(Infrared Focal Plane Arrays) detector were presented.The available RIE equipments and etch principle were analyzed respectively according to the characteristics of HgCdTe epitaxial material in detail.The influences of etching gas ratio,chamber pressure,ICP(inductively coupled plasma) power and RF(radio frequency) power on HgCdTe etch pattern were investigated by using ICP enhanced RIE(reactive ion etching).Then a stable dry etch technique is obtained with clean and smooth etch surface,good pattern profile,good uniformity and high etch rate.