Abstract: In order to solve the problem of uneven brightness and decreased sharpness of the projected image caused by the laser speckle rising from the coherence of the light source in the laser projection display,introducing laser into a vibrating multimode optical fiber,the output laser mode field beats between the various modes at high frequency,and homogenized and incoherent results were obtained.The results show that the speckle contrast ratio of the projected image is significantly reduced to 4% or less,which the human eye is difficult to distinguish.