报导了２１μｍＣｏ∶ＭｇＦ２激光器在室温下的实验结果，得到了０２７９Ｊ的２１μｍ激光，器件效率为１４５％测定了Ｃｏ浓度为３％（ｗｔ）的ＭｇＦ２晶体对１３４１４μｍ线的偏振吸收系数，测量结果表明，对该谱线π偏振和σ偏振的吸收系数分别为０８０４ｃｍ－１和０５１６ｃｍ－１．激光实验结果计算得到该晶体２１μｍ线的激光跃迁截面为２６１×１０－２１ｃｍ２． The experimental results of 21μm Co:MgF2 laser at room temperature were reported. The 21μm laser with 0279J was obtained and the device efficiency was 145%. The effects of MgF2 with Co concentration of 3% The results show that the absorption coefficients of π-polarization and σ-polarization for this line are 0804 cm -1 and 0516 cm -1, respectively. Laser experimental results show that the 2 +1 μm line of the crystal laser transition cross section of 2  61 × 10-21cm2.