The invention relates to micro laser projection display technologies, particularly provides an optical structure, system and method for eliminating laser projection speckles, and aims at overcoming the defect that the energy efficiency is reduced when the spatial differences are increased to eliminate the speckle phenomenon in current micro laser projection display technologies. The optical structure includes a laser light source, a light mixing stick, a digital micro-mirror device and a DMD array, laser beams emitted by the laser light source is subjected to multiple total reflection in the light mixing stick, emergent lights formed by the multiple total reflection are incident on the digital micro-mirror device which is loaded with digital holography source information, and laser beams emitted from the digital micro-mirror device go through the DMD array and reach a display terminal. On the premise of effectively eliminating the speckle phenomenon, the optical structure, system and method solve the contradiction between speckle elimination and energy efficiency in the current laser projection display technologies. Meanwhile, the optical structure, system and method have the advantages of being simple in structure and easy to implement.