With the progress of science and technology, electronics, machinery and other fields to the miniaturization, miniaturization of the direction of development, the heat dissipation requirements for such products are also increasing. The micro-channel heat ex-changer becomes the main cooling equipment after miniaturization because of its small volume and strong heat transfer capability. Its performance has also become one of the hot spots among domestic and foreign scholars. This special issue focuses on the performance of micro heat pipe and micro heat channel. The subjects of Micro-thermal channel heat transfer thermal imaging, thermal performance of micro-heat pipes in different environments can be discussed. First of all, the materials of micro heat channel and the effects of different materials on heat transfer performance can be studied. Next, the application of micro-thermal pipes in different environments is also the direction of interest, such as, heat transfer technology based on micro-heat pipe, and research on thermal recovery performance of lampblack based on micro-thermal pipes. This special issue accepts review papers, theoretical papers and applied papers. You are welcome to contribute enthusiastically.