Abstract: Orthogonal design methodology was applied to investigate the design parameters' impact on multi-objectives,including flame length,wall temperature and injector panel temperature of GH₂/GO₂ fired gas shear coaxial multi-injectors chamber.Variance analysis and range analysis indicate that ratio of hydrogen-rich gas velocity to oxygen-rich gas is a dominant factor for flame length and wall temperature,and small thickness of injector is beneficial for reducing injector panel temperature.The interaction effect of the design parameters varies sharply for different objectives.The result of response surface shows that low pressure drop of oxygen-rich gas,high velocity ratio and appropriate injector thickness are advantageous for balance performance.