The invention relates to a method for evaluating the dispersed state of nano ZnO in pitch. The method comprises the steps that dispersed state parameters of the nano ZnO particles in the pitch are obtained based on a digital image processing technology, the dispersed uniformity of the nano ZnO particles is evaluated by adopting area ratio variation coefficients and meristic variation coefficients, the nano ZnO particle dispersed degree is evaluated by adopting the average particle diameter, and therefore the dispersed state of the nano ZnO in the pitch can be quantitatively evaluated. The defect that the dispersed state of the nano ZnO in the pitch cannot be quantitatively evaluated is overcome. Meanwhile, the method is simple, the operation process is simple, the evaluation result is accurate, technical support is provided for researching the new and old pitch mixing state, guidance is provided for thermal regeneration of the pitch mixed material, and popularization is facilitated.