A　technique　for　the　real-time　measuring　of　the　output　power　of　high　power　diode　laser　is　developed　to　improve　the　laser　quality.　A　lens　placed　at　an　angle　of　45°　in　the　system　is　used　to　sample　the　output　light　of　laser.　A　piece　of　ground　glass　was　used　to　uniform　the　beam　power　density.　The　photoelectric　detector　received　an　optic　signal　and　converted　it　into　electric　signal.　This　feeble　signal　was　processed　by　amplification　circuit　with　a　filter.　Finally,　the　signal　was　inputted　into　the　control　unit　for　displaying　and　controlling.　This　approach　helps　us　to　achieve　real-time　detection　for　the　high-power　diode　laser.　This　measuring　system　was　tested　with　a　300W　high-power　diode　laser.　If　applying　this　kind　of　real-time　measurement　system　to　high-power　diode　laser,　it　would　bring　in　significant　value　in　laser　processing.