Progress on key technology of mid-infrared liquid crystal optical phased arrays was summarized. The fundamental principles and schemes were introduced. Meanwhile, graphene and mid-infrared liquid crystal were the key technique to realize the practical mid-infrared liquid crystal optical phased array. The latest development on these two technique were emphasized on the topic of non-mechanical mid-infrared laser radar system. The recent development on mid-infrared liquid crystal included tolane liquid crystals and fluorinated liquid crystal. The transparent spectrum and its composite were both given including their working conditions. The recent development on mid-infrared transparent conductive films included graphene, nano-metal-network, graphene-metal composite film. The fabrication process of each kind of film were given, also their properties such as transparent spectrum and mechanical attach forces were introduced in detail.