Abstract: The quantitative ability of multi-mode total focus method for defects with different inclination angles in butt weld of steel plate was studied. The rectangular slot was used to represent the sliver defect in the weld, the single-frequency scattering coefficient of the slot was obtained by the finite element method, and combined with the wave propagation model for full matrix data simulation, the slots with different dip angles were simulated and imaged. The results showed that different modes had different coverage for defect angle. Three half-span modes, LL-L, TT-T and TT-L, can cover the defects of 0~40°dip angle, and five full-span modes, TL-LT, LL-LL, TL-TL, TT-TL and TT-LL, can cover the defects of 10~70°dip angle, they had the best characterization ability for defect angle, and should be given priority in practical detection. In addition, the quantitative identification of slot length was easily affected by the scattering intensity, and the quantitative identification with the same threshold was not suitable for all modes.