The invention relates to the technical field of fishing boat leaked oil collection and purification, and in particular, relates to a fishing boat leaked oil collecting and purifying device; the interior of a box body is provided with a first partition plate, a second partition plate and a third partition plate from left to right successively; the bottom of the second partition plate is provided with a through hole; a feeding hopper is arranged between the second partition plate and the third partition plate; a water outlet is formed in the bottom of the box body; the water outlet is arranged between the first partition plate and the left side wall of the box body; the third partition plate is provided with an oil-passing through hole; the right side wall of the box body is the right side wall of the box body; the outer wall of the right side wall of the box body is provided with an oil outlet pipe communicating with the interior of the box body; the horizontal height of a feed end of the oil outlet pipe is less than that of a discharge end of the oil outlet pipe; the horizontal height of the oil-passing through hole is higher than that of the feed end of the oil outlet pipe; the horizontal height of the top of the first partition plate is less than that of the oil-passing through hole. When in use, the fishing boat leaked oil collecting and purifying device achieves power-free oil collection and purification, and not only can collect oil but also can save costs.