Three-factor quadratic general rotary experiment design was made to optimize three main process parame-ters of the chlorine dioxide bleaching of oxygen-delignified bagasse pulp, namely, the ClO₂ dosage, the NaOH do-sage and the bleaching time. Besides, a quadratic polynomial nonlinear regression model describing the relationshipsbetween the process parameters and the Kappa number, the brightness as well as the absorbable organic halide(AOX) content was constructed. The results show that the constructed regression model passes the significance testand fits well, that the three parameters affect the Kappa number, the brightness and the AOX content in a order of ClO₂ dosage>bleaching time>NaOH dosage, and that, in the optimal conditions, namely a ClO₂ dosage of 0.79%,a NaOH dosage of 0.43% and a bleaching time of 53min, the predicated Kappa number, brightness and AOX con-tent respectively reach 1.83, 73.3% ISO and 10.8 mg/ L, which are close to the experimental values of 1.76,75.0%ISO and 11.3mg/ L.