Reasonable determination of the anchorage scale in port is beneficial to making full use of berth and channel resources and avoiding the waste of investment.At present，the study on the determination of the anchorage scale does not consider the influencing factors of multiple anchorages，complex channel networks，multiple wharfs and berths，and ship-to-shore handling equipment.Therefore，this paper proposes a method to determine the reasonable anchorage scale in port based on system simulation.By constructing a system simulation model，the paper simulates the actual operation process of the “anchorage-channel-berth” system，calculates the number of ships waiting to be berthed in the anchorage and waiting time，and determines the reasonable anchorage scale，which is applied to the determination of the anchorage scale in a Chinese port.The results show that the maximum number of ships waiting to be berthed in the anchorage or the number of ships waiting to be berthed in the anchorage with significant duration obtained from simulation statistics can be taken as the designed anchorage capacity.This method can provide support for the rational and scientific determination of the anchorage scale.