In order to study on the feasibility of achieving 2 μm laser by using Yb³⁺/Tm³⁺/Ho³⁺ codoping in germanium glass,the effects of doping concentration of three rare-earth ion on the nearly 2 μm luminscence were researched,so optimized doping concentration can be acquired.The results show that when the doping mole fraction of TmF3 is 1%,the 2 μm luminscence of Ho³⁺ increases with doping concentration of Yb3 + ions.However,as the doping mole fraction of TmF3 is increased to 3%,the 2 μm luminscence intensity of Ho³⁺ is reduced with increasing doping concentration of Yb3 +.The near 2 μm luminscence of Tm³⁺ can be raised by increasing doping concentration of Yb³⁺ ions and it is more apparent at high doping concentration of Tm³⁺ ions,which could weaken the luminscence of Ho³⁺ relatively.On the whole,the 2 μm luminscence of Ho³⁺ is significantly effected by the doping concentration ratio of Tm3＋/Ho³⁺.When the three doped samples were pumped by 980 nm LD,both the high doping concentration of Tm³⁺ ions and low doping concentration of Ho³⁺ ions can lead to the reduction of 2 μm luminscence intensity of Ho³⁺.