As one of the characteristics of detector components, the responsivity non-uniformity has an important impact on its practical applications, especially in the low-background space application. The uneven contact-hole size of large-format detector chip is one of the factors which lead to the non-uniformity of device responsivity. The contact-hole etching process of the large-format long-wave infrared detector chip with 1280×1024 pixels is studied, and the optimization measures are proposed. The result shows that the proposed method can improve the uniformity of the etching process, thus improving the responsivity non-uniformity of detector components.