Abstract: In order to reasonably schedule tugboat operation, effectively improve tugboat utilization factor and reduce the waiting time of vessels, the multiprocessor tasks scheduling theory was applied to analyze the tugboat operation scheduling problem according to the characteristics of the tugboat operation. Considering the minimum operation distance of the tugboats, an optimization model was built to minimize the maximum makespan of all ships. The evolutionary strategy algorithm was applied to optimize the tugboat operation scheduling, and an encoding and coding method based on the roulette probability assignment was proposed. The recombination operator based on three-point crossover and the mutation operator based on the gene cross-over in the individual were designed. The results of a case study show that the optimization results achieved by the evolutionary strategy algorithm is obviously better than those by the simulation and the particle swarm optimization algorithm. When using real encoding, the minimum of the maximum makespan obtained by the proposed optimization method is 356 min, which is less than the simulation results by 117 min. When using integer encoding, the minimum of the maximum makespan is 369 min, less than the simulation results by 104 min. This verifies the effectiveness of the minimum operation distance rule for tugboats.