Long-wave mercury cadmium telluride materials are influenced by factors such as structure and composition. During the preparation of devices, material damage can occur to the etched electrode contact holes, which affects the imaging performance of the chip. The existing inductively coupled plasma (ICP) equipment is used to etch the electrode contact holes of long-wave mercury cadmium telluride chips, and step-by-step etching is used to avoid damage. Although this method can improve the imaging quality of chips, its efficiency is low and it is difficult to apply to large-scale fabrication. In order to improve etching efficiency and achieve large-scale device preparation, a one-step forming process is developed for the electrode contact holes of long-wave mercury cadmium telluride chips by co-optimizing the RF power of the upper and lower electrodes of the ICP etching machine. After verification by intermediate testing, the blind element rate of the long wave detector (320×256 pixels with a pixel pitch of 30 m) is only 026%. This process can achieve low damage electrode hole etching and can be extended to the preparation of large-scale long-wave infrared chips.