The metamaterial absorber consists of metallic resonator, dielectric layer and metallic ground plane. Using impedance matching theory or multi-reflection interference theory can explain why the metamaterial structure can absorb the incident waves perfectly at one specific resonance absorption peak, qualitatively or quantitatively. However, metamaterial structure can only absorb incident waves perfectly at a specific frequency once the structure parameters are fixed. Therefore, methods to obtain tunable metamaterial absorbers have attracted widespread attention. In recent years, the author′s team has focused on how to achieve the dynamic modulation of metamaterial absorber. Based on this, the ways to modulate the absorption of terahertz metamaterial absorber are reviewed, including varying the dielectric layer thickness, modulating the conductivity of ground plane, and adding photoconductive materials to the gaps of the metallic resonator. A brief outlook is presented by focusing on the absorption modulation of terahertz metamaterial.