Polymer steric stabilization is the main mechanism of ceramic suspension stabilization. In this paper, the alumina suspension stabilized by steric mechanism was studied. The influence laws of volume fraction of suspension, content of polymer and particle size on the elastic modulus were studied through rheological property tests. The results indicate that the two rheological testing modes of steady-state shear and oscillatory shear prove that the suspension has obvious elastic characteristics. It is determined that the core factor affecting the elastic modulus of alumina suspension in steric stabilization is the particle surface spacing, due to the particle surface spacing affecting the compression degree of adsorbed polymer. Increasing the volume fraction of suspension and decreasing the particle size both improve the elastic modulus of the system by reducing the particle surface spacing and the thickness of compressed adsorption layer, meanwhile elasticity increases, and the stability of suspension is affected.