In order to obtain single crystal with brilliant quality and large size to accommodate the requirement of high-power solid state Mid-IR laser, the Cr2+
: ZnSe single crystal is grown in the all-graphite cavity with the surrounding of super-high pressure and temperature by the method of Bridgeman. By means of the X-ray Diffraction(XRD), Transmission Electron Microscope(TEM), absorption and fluorescence spectra, the structure, optical properties of the crystal are investigated. Meanwhile, energy level structure and transition mechanism of Cr2+
in the Cr2+
: ZnSe crystal are also studied. Experiment results show that the as-grown Cr2+
: ZnSe crystal with well-distributed structure and stable physical properties has much wider spectral range of 1.9-3.0 μm range under the pumping source of 1.97 μm laser. It is applicable to obtain a mid-IR laser at the range of 2-3 μm.