Tunable mid-infrared lasers based on nonlinear optical frequency conversion play a vital role in application fields including environment monitoring, remote sensing and biomedical diagnosis. The long-term development of near-infrared laser technology has led to a high degree of commercialization of near-infrared pumped lasers. The utilized of the commercial near-infrared laser as the pump source is easy to realize miniaturization, high power and high stability operation of the tunable mid-infrared laser. Nonlinear optical crystal, which is the core component of the tunable mid-infrared laser, determines the output characteristics of the mid-infrared laser source. Suffering from multi-phonon absorption, the tunable output band of traditional oxide crystals is limited to below 4 μm. On the other hand, the most commonly used ZnGeP₂ has strong two-photon absorption at 1.06 μm. High-quality mid-infrared crystal pumped by near-infrared laser have remained of great interest in recent years. In this paper, we reviewed the application of the newly developed non-oxide crystals in mid-infrared laser generating. BaGa₄Se₇ and BaGa₄S₇ have wide transparency range, high laser damage threshold and nonlinear coefficient. Using a low repetition frequency pump source, the tunable output range covers the entire mid-infrared band, and the output energy achieves mJ-level even in the long wave infrared band. Under a pump repetition rate of hundreds of Hz, the average output power in the mid-wave infrared band reaches 1 W. However, due to the low thermal conductivity of these two crystals and the near-infrared absorption, there is no report on the near-infrared laser pumped source with repetition rate of kHz-level and average output power of W-level. Subsequent research mainly focused on the improvement of pump and crystal cooling conditions. LiGaSe₂ and LiGaS₂ crystals are suitable for near-infrared ultrashort pulse pumping to produce mid-infrared lasers due to their large band gap. In particular, LiGaS₂ crystal has high laser damage threshold and thermal conductivity. At present, there have been many reports about the generation of mid-infrared laser with repetition frequency of kHz or even MHz. The femtosecond laser source based on LiGaS₂ crystal has been applied to the research of vibration sum-frequency spectrum detection, biomolecular fingerprint spectrum recognition, etc. However, due to the small geometric size of LiGaSe₂ and LiGaS₂ crystals in the existing reports, their output powers under nanosecond laser pumping are relatively low. In addition, LiGaSe₂ and LiGaS₂ crystals have an obvious absorption peak near 8 μm. The transmittance above 8 μm decreases rapidly, so it is not suitable for the generation of long-wave infrared lasers. The improvement of crystal synthesis and growth process will help to play the potential of LiGaS₂ crystal in broadband tuning and high-power laser generation. LiInS₂ and LiInSe₂ are newly developed crystal with high band gap. The laser damage threshold of LiInS₂ crystal and LiInSe₂ crystal is relatively low, so the existing reports mostly based on picosecond/femtosecond laser system. Under nanosecond laser pumping, it is difficult to achieve mJ-level, high energy mid-infrared laser generation. The current research is mainly focused on broadband tunable mid-infrared laser generation. Although the current output average power is low, LiInS₂ and LiInSe₂ crystals have high thermal conductivity and low thermo-optical coefficient, so these crystals have the potential to be used in the generation of high repetition rate and high average power mid-infrared lasers. At present, the main bottleneck lies in the synthesis and growth process of large size and high-quality crystals. CdSiP₂crystals have high thermal conductivity, nonlinear coefficient and band gap, and the cutoff wavelength in the short-wave direction is relatively short. Using a near-infrared laser pump source, the output energy reaches mJ-level under low repetition rate operation. The output average power exceed 100 mW with repetition frequency of several MHzs. High efficiency 6~7 μm generation with 1 064 nm laser pumping can be achieved under non-critical phase matching condition. The output band can be expanded to 2~8 μm by combining pump wavelength tuning and angle tuning. CdSiP₂ also has great potential in the on-chip application. However, the laser induced damage threshold of CdSiP₂ crystal is low, and the transmittance above at 8 μm decreases rapidly, which limits its application in high power and long-wave infrared laser generation. Quasi-phase-matched crystals represent a new research direction of mid-infrared nonlinear optical crystal materials. Quasi-phase matching technology can utilize the maximum nonlinear coefficient and avoid walk-off effect, so tunable mid-infrared source based on quasi-phase-matched crystals have the advantages of high conversion efficiency and can realize mid-infrared output in the whole transparency band. Orientation-patterned gallium phosphide (OP-GaP) has high nonlinear efficient and thermal conductivity. It has great application potential in high power and high efficiency middle infrared laser generation. However, the synthesis of high-quality single crystals with large aperture and high uniformity are difficult. The improvement of material growth technology will significantly improve the output power of existing mid-infrared lasers based on quasi-phase-matched crystal materials. The further research will focus on: 1) improvement of the crystal quality, especially the size and the uniformity of the crystal; 2) improvement of the output characteristics of the near-infrared pump laser; 3) development of the new nonlinear optical crystals.