Working on a discharge-driving continous wave(CW) HF chemical laser,using the oscillating threshold condition and Rigrod theory,and considering with the data of overseas′ HF overtone chemical laser,the overtone cavity mirrors with band selectivity coating were chosen to study.3.5 W of overtone laser is obtained on the 1mm downstream station of H2 injecting orifices.The spot size at 60 cm distance is about 10 mm×7 mm,and the overtone efficiency is 10%.The spectra contain lines P20(6) and P20(7),and the mode is TEM00.There is a little of fundamental laser going with overtone laser.The analysis of results indicates that this is mostly because of the bad coating of mirrors,which is also one of the difficulties to obtain the HF overtone laser,recently.When studying this experiment again,the laser only obtains many watts of fundamental power,the spectra contain lines P2(3) and P2(4).And the possibility reason is optical coating degradation of resonator mirrors.