Abstract: In allusion to the most commonly used KTiOPO4 (KTP) frequency-doubling crystals, the influence of tilting misalignment and rotary misalignment on conversation efficiency in frequency-doubled laser was discussed. Based on the principal axis coordinate transform, the model of tilting misalignment was established, what-s more, the process of tilting and rotary misalignment was analyzed in detail theoretically and experimentally. The results show that, in the case of tilting misalignment, two different narrow peak values of conversion efficiency appear with the variation of directions, and the bigger tilting misalignment value, the smaller included angle of peak value direction, in other direction, the conversion efficiency is zero; for rotary misalignment, type-Ⅰ and type-Ⅱphase matching conversion efficiency vary with misalignment angle for and /2 cycles, respectively.The results may provide a promising route to the design of frequency-doubled laser.