The paper aims to formulate a more efficient and low-cost dual-ferry ship scheme during the peak period of traffic flow. Through analysis on the queuing characteristics of waiting vehicles during rush hours, combining with a formula in batch processing of the M/Mr/1 queuing system of the queuing theory, the theoretical relationship between the loading capacity of ship and the queue length of cars theoretically. Under the actual situation of a ferry enterprise, the queue length L was calculated respectively in the case of Mi=21, 22, 24, 27, 29, 30 and TAii-1=6.7, 7.1, 7.6, 9.3, 9.9 and 15.1. After using the statistical method, it can be find that Mi had a significant influence on the queue length L for waiting vehicles (results of the statistical analysis: P < 0.05), and the functional relation curve between the queue length and the ship's load was fitted. Under the condition of setting service intensity of 0.9, and combine with the cost of ferry, when the arrival rate of the queue system λ1=2 vehicles/minute, ferry ship with the loading capacity of 16 cars can meet the ferry demand during peak period with a 3.2 minute arrival time interval.