Entropy is a common description method in the analysis and research of optimization system. To address the lack of in-depth analysis of the inherent relationship between the dynamic behavior and entropy of different optimization systems, an optimization algorithm entropy based on quantum dynamics was proposed. Firstly, based on the similarity between Brownian motion and sampling behavior in physics, a Brownian motion description method for optimization problems was proposed. The mechanical expression of optimization problems was transformed into the form of energy and introduced into the Schr?dinger equation, and an optimization algorithm based on quantum dynamics was proposed. Then, the probability expression of optimization problems under the Schr?dinger equation was combined to obtain optimization algorithm entropy. Finally, the random behavior of particles under constraint of the objective function was analyzed, and the relationship between basic search behavior of optimization systems under quantum dynamics and entropy was given. By tracking and analyzing the dynamic behavior and entropy change trend of optimization systems from three different aspects: reference energy, free particle kinetic energy, and objective function disturbance, the correlation between entropy and search behavior of optimization systems was verified through experiments. Experiments results show that optimization algorithm entropy based on quantum dynamics can deeply analyze optimization process, providing a new idea and method for studying optimization algorithms.