Abstract: Energy supply is a prerequisite for offshore island development. Purely independent micro-grid energy supply methods often face certain reliability problems, and the high construction and maintenance costs of submarine cables limit the development and utilization of offshore islands to a large extent. Therefore, this paper proposes a flexible energy supply network planning strategy for offshore islands considering the participation of electric vessels (EVs). Firstly, for the relative locations of typical offshore inhabited islands and resource islands as well as their renewable-energy output characteristics, a flexible energy supply network architecture is proposed, which includes EV energy links to connect inhabited islands, resource islands, and grid parallel points, so as to make full use of the renewable resources on uninhabited islands and the stable support capacity of the large grid. On this basis, a network planning model for hybrid continuous-intermittent energy flow is developed with the objective function of maximizing the grid revenue of the islands during the planning period. In addition, a two-stage solution algorithm is put forward, where the first stage estimates the number of EVs, and the second stage determines the optimal solution to the planning model. The simulations demonstrate the superiority of the proposed planning scheme. This paper provides a new way of thinking for the power supply to offshore island loads and the exploitation of renewable energy.