The invention specifically relates to a metal film differential pressure filter and aims to provide a metal film differential pressure filter which has the advantages that a backwashing system and a blowdown system are combined, backwashing sewage is discharged in time, the backwashing time is reduced, and the filter efficiency is improved. The metal film differential pressure filter comprises a body, a filtering system, the backwashing system, a transmission system and the blowdown system, wherein the filtering system is positioned in the body, the backwashing system is positioned in the filtering system, the transmission system is connected with the backwashing system, and the blowdown system is positioned in the filtering system; the backwashing system comprises a hollow shaft which is concentric with the body, a high-pressure backwashing pump is arranged, so as to supply water to the body through a high-pressure backwashing pump inlet pipe, a high-pressure backwashing device with a high-pressure water injection nozzle is arranged outside a fine filter screen and is communicated with a high-pressure inlet cavity, and the high-pressure water injection nozzle is inclined towards the blowdown system; a blowdown device with a suction nozzle corresponding to the high-pressure water injection nozzle is arranged on the inner side of the fine filter screen, and an end opening, which is close to the blowdown system, of the suction nozzle is greater than that which is close to the high-pressure inlet cavity. The metal film differential pressure filter has the advantages of short backwashing time and low water consumption and can be quickly restored to be in an initial state.