The invention discloses an operation method, device and system of a mobile power supply device. The operation method comprises the following steps that relevant information of a user who sends a use application is acquired, and an order is generated; based on the obtained relevant information of the user, the information of the mobile power supply device suitable for the user is screened out; andthe position information in the related information of the user and the information of the mobile power supply device suitable for the user are sent to a delivery terminal, so that the delivery terminal moves to the mobile power supply device and delivers the mobile power supply device to the position contained in the related information of the user, and thus the electric connection and charging of the mobile power supply device and a ship of the user are realized. According to the operation method, device and system, the operation management of the mobile power supply device is realized by adopting an internet + and a sharing mode, the rental service of the mobile power supply device is provided, and the mobile power supply device can be conveniently and fast used for supplying power to ships docked in the river center.