Acidithiobacillus caldus (A. caldus) is one of the predominant biomining bacteria, which shows application prospect in biological metallurgy. It can enhance the biomining efficiency together with iron oxidation bacteria in mixed biomining system. Based on the published papers and our study on this bacterium, we described the research progress on it from four aspects, including the biomining mechanism, arsenic-resistant mechanism, genome study and genetic reconstruction. Furthermore, we discussed the prospects of research on A. caldus.