The invention discloses a path planning method and device, and an inspection robot. The path planning method specifically comprises the following steps: initializing information, determining the quantity of all docking points and all task points, a task starting point, a task ending point, a task list and the task point quantity; reading a shortest distance matrix containing all the docking pointsand all the task pints, a nearest neighbor matrix, the task starting point, the task ending points, the task point quantity and the task list; performing pre-treatment on the task list to obtain a latest task list; calculating the shortest distance matrix according to the latest task list to obtain a current shortest distance matrix corresponding to the latest task list; according to a preset improved ant colony algorithm, performing path calculation on the task points in the latest task list to obtain a task point sequence; performing refining treatment on the task point sequence according to the nearest neighbor matrix and preset one-way road section information to obtain a task point inspection sequence.