Abstract: In order to obtain the single-mode output of a diode laser in 795nm,a system of anti-reflection-coated frequency-tuning diode laser with grating-feedback extended-cavity was presented.Experiments were executed in the laser.It works in 795nm with a mode-hop-free continuous scanning range of roughly 7.6GHz.The result shows,the output linewidth is about 2.5MHz and the output power can achieve more than 43mW with a 110mA injection current.The diode laser can be very useful in the research of atomic coherent effect when laser interacts with Rb atoms.