Metamaterial based near perfect absorbers have a wide range of potential applications in sensors, photovoltaic devices, thermal imaging and other fields due to their unique absorption properties. However, the absorption characteristics of traditional absorbers are based on their static structure. When the structural parameters is fixed, their absorption characteristics is structure locked. In this work, we design a broadband dynamic tunable absorber based on pyramid array structure using phase change material VO2. The absorption spectrum of the structure in the range of 0.4 ~ 8um is simulated by 3D finite difference time domain method. By controlling the phase transition of VO2and structure parameters of pyramid array, the dynamic tunable absorber based on VO2 shows excellent switching characteristics, and the difference of absorptiion before and after phase transition in 3 ~ 8um band can reach more than 0.75.