The invention discloses an unmanned ship path planning method based on a Q learning neural network. The method comprises the following steps: a) initializing a storage area D; B) initializing a Q network, a state and an action initial value; C) randomly setting a training target; D) randomly selecting an action at a to obtain a current reward rt and a next moment state st + 1, and storing (st, at,rt and st + 1) into a storage area D; E) randomly sampling a batch of data from the storage area D for training, namely a batch (st, at, rt, st + 1), and considering the state when the USV reaches the target position or exceeds the maximum time of each round as the final state; F) if the st + 1 is not the final state, returning to the step d), if the st + 1 is the final state, updating Q networkparameters, returning to the step d), and repeating n rounds to finish the algorithm; And g) setting a target, and carrying out path planning by using the trained Q network until the USV reaches the target position. The decision-making time is short, the path is more optimized, and the real-time requirement of online planning can be met.