Abstract: To study the efficient broadband third-harmonic generation(THG) technology,the process in CsLiB6O10(CLBO) crystals was studied through numerical simulation based on split-step Fourier transformation and the fourth-order Runge-Kutta method.The dependence of conversion efficiency on input intensity and bandwidth of 1ω waves was analyzed in type-Ⅰ/type-Ⅱ and type-Ⅰ/type-Ⅱ/type-Ⅰ quadrature schemes respectively.As a comparison,broadband THG in KDP crystals was also investigated.Conversion efficiency up to 60% with a bandwidth of 650GHz was achieved in the type-Ⅰ/type-Ⅱ/type-Ⅰ quadrature scheme while the temporal profile of 1ω was assumed to be super-Gaussian(40,exponent) with an intensity of 3GW/cm2.An increase of 250GHz was accomplished in CLBO crystals compared with that in KDP crystals.The obtained results show that broadband THG conversion efficiency can be improved availably in the type-Ⅰ/type-Ⅱ/type-Ⅰ quadrature scheme with CLBO crystals.