The mid-infrared band of 3–5 μm is located in the smallest weakening infrared window in the atmosphere, which contains the characteristic absorption or vibration energy bands of most molecules, and is widely used in remote sensing, harmful gas detection, medical and military fields. At present, the preparation of chow-glass fiber doped with rare earth ions is one of the effective means. In order to deeply understand the effect of different concentrations of rare earth ions on the optical properties of chow-glass, the preparation and properties of Pr3+ chow-glass and fiber were studied. In the preparation process, the melting quenching method is used, and the main preparation process is given. According to the preparation process, the experimental sample is prepared. In the study of optical properties, Differential scanning calorimetry (DSC), X-ray diffraction (XRD), glass absorption spectroscopy, near and middle infrared fluorescence spectroscopy and Raman structure analysis were carried out. The results showed that different concentrations of Pr3+ ion doping concentration had different effects on the infrared luminescence intensity of samples. The final conclusions are summarized as follows: First, above 100℃, the sample has strong crystallization resistance, which is conducive to the drawing of active fiber; Second, with the increasing of Pr3+ concentration, the sample density increased, but the increasing trend was not obvious, the molar volume showed a decreasing trend, and the refractive index did not change significantly. Thirdly, when Pr3+ concentration increased to 0.3 mol%, the sample did not appear crystallization phenomenon, and when the concentration continued to increase to 0.4 mol%, there was an obvious crystallization peak. Fourth, the choice of 1550 and 2020 nm laser as the pump light source, can maximize the efficiency of the pump; Fifth, the optimal doping concentration of Pr3+ ions in the glass of the system is 0.1 mol%. When the concentration exceeds this concentration, the quenching phenomenon will occur between rare earth ions, and the ideal fluorescence emission cannot be achieved. The optical properties of chorium-based glass fiber doped with Pr3+ ions are different in general, and the best concentration can be selected according to the actual requirements to obtain high quality products.