In this work, we constructively developed a highly efficient combustion synthesis (CS) strategy as a new route for the facile preparation of SiAlON based phosphors. The doping of Eu2+ endued the Ca-α-SiAlON ceramic powders with outstanding photoluminescence behaviors of strong yellow emission peaking at around 580nm under excitation of near-UV or blue light. Meanwhile, the as-synthesized phosphors were also featured with high phase purity, favorable uniformity and equiaxial morphology. In the CS system, the Si and Al reactants both played significant roles as comburents, which directly determined the systematic energy in the reaction. Therefore, the distinct impact of Si/Al ratio in the comburents on the phase composition, microstructure and photoluminescence properties were thoroughly studied. The experimental results demonstrated that the appropriate ratios of Si and Al in the comburents would evidently optimize the comprehensive properties of as-synthesized Ca-α-SiAlON:Eu phosphors, which showed great potential in the application of LED light source. In addition, a blue-shift phenomenon in emission spectra with the increase of Al ratio was observed and rationally revealed.