Micro-sized ZnO superstructures self-assembled by hexagonal prisms were achieved by direct thermal decomposition of Zn(NO3)(2)center dot 6H(2)O. The results showed that the as-prepared ZnO superstructures had superb catalytic effect on the AP pyrolysis. When ZnO superstructures with a 2% mass ratio were added, the pyrolysis temperature was decreased by 154.3 degrees C and the activation energy of AP pyrolysis was reduced by 61.7%. Additionally, introduction of ZnO superstructures led to a 2.87-fold increase in the exothermic heat during AP pyrolysis. The excellent catalytic activity of ZnO superstructure could be attributed to its small band gap width, existence of oxygen vacancies and good dispersion.