Abstract: In this paper,two rapidly tuning techniques which include a six surface mirrors scanning a fixed grating and a high frequency stepping motor controlling a diffraction grating are presented.It is illustrated in experiments that the means of stepping motor is better than that of rotating mirror.Laser operated at 51 emission lines is obtained,and the pulse energy of laser radiation at first order is about (30～100)mJ.The system can be tuned rapidly different rotational lines with a single laser,the tuning time interval to different lines is not large than 10ms.