This paper tries to introduce the reader to the method of using photochemical re-action to copy holographic optical elements(HOEs)in relief.The holographic blazing gratingso copied is groove depth adjustable phase modulability enlarged through copying and 3.3times the diffraction efficiency(DE)of the original grating.It is expected that the newmethod will lead to the mass production of the light-weight HOEs at low cost. This paper tries to introduce the reader to the method of using photochemical re-action to copy holographic optical elements (HOEs) in relief. The holographic blazing grating is copied is groove depth adjustable phase modulability enlarged through copying and 3.3times the diffraction efficiency (DE) of the original grating. It is expected that the newmethod will lead to the mass production of the light-weight HOEs at low cost.