Cavity optomechanics, as a cross-discipline between nanophotonics and quantum mechanics, provides a unique platform for investigating optomechanical coupling between photons in microcavities and phonons from mechanical modes. It has a wide range of potential applications in quantum physics, and now it has become a hot topic. A theoretical scheme to enhance the sum sideband generation (SSG) via a two-level atom ensemble is proposed. The effect of the atomic ensemble’s detuning frequency on the efficiency of the SSG is considered by introducing a two-level atom medium. The results indicate that the efficiency of the generating sideband can be significantly enhanced under either red or blue detuning of the atoms, with greater dependence and more pronounced enhancement under the red detuning. In addition, we also consider the effect of pump power, which can effectively enhance the intensity of the output signal by selecting the appropriate pump power. More interestingly, the sensitivity of SSG to atomic detuning also indicates that the precise control of the atomic detuning frequency can achieve the fine-tuning of the SSG process. Furthermore, the cavity-atom coupling strength and atom decay rate are discussed for the transmission characteristics of the sum sideband signals. It is found that the efficiency of SSG can be effectively adjusted by the cavity-atom coupling strength and atom decay rate. The results show that the efficiency of SSG can be significantly improved by optimizing system parameters. The method of enhancing SSG may have potential application prospects in measuring high-precision weak forces and on-chip manipulation of light propagation.