The invention provides a fan engine room hood which comprises a hood body; the hood body comprises a ventilation structure; the ventilation structure comprises a first area and a second area which are separated by a separation net; the first area is a cylindrical closed area surrounded by a cylinder wall; a plurality of groups of air intake grilles are arranged on the cylinder wall of the first area; two sets of purification cans are embedded in the cylinder wall; an induced-draft fan is arranged at an end part of the cylinder wall; at least two groups of deposition tanks are arranged at the bottom of the room wall of the second area; an air intake passage leading to the hood body is formed in the second area; and the open/closed state of the air intake passage is controlled by fitting between an elastic support and a sealing pad. As air entering the hood body is purified and dried sufficiently via the two stages of air intake areas, the fan engine room hood has the advantages of reasonable structure, high convenience in use and high easiness in maintenance.