A novel wavelet transform processor (WTP) using SAW device with unequal electrode width(UEW) has been developed to eliminate the effect of the piezoelectric substrate of the WTP using SAW device on the frequency characteristic and the effect of the electrode number of the output interdigital transducer(IDT) on the bandwidth as well as to solve the problem of diffraction. This WTP using SAW device with UEW uses the X112°Y LiTaO3 piezoelectric substrate with the electromechanical coupling coefficient of 0.64%, the electrode numbers of the output IDT were 36 and the input IDT used the unequal electrode width and uniform acoustic aperture. A WTP using SAW device with UEW sample with scale of 2-2 has been fabricated. The experimental results confirmed that the WTP using SAW device with UEW had the features of smooth frequency characteristic curve, -3 dB bandwidth of 1.072 MHz and no diffraction.