2 μm band laser has a wide range of applications, not only in the fields of lidar, laser ranging, and medical surgery, but also as a pump source for mid and long wavelength infrared lasers. Using laser diodes to directly pump thulium-doped crystals to obtain lasers in the 2 μm band is a direct and efficient technical means, which has attracted wide attention. This paper introduces the research progress of Tm∶YAG, Tm∶YAP, and Tm∶YLF pulsed lasers, and makes a summary and prospect.