The invention relates to a film spreading system, which comprises a supply device, a film spreading device and a cutting device, wherein the supply device is used for supplying continuous carbon nanotube films; the film spreading device is used for spreading the carbon nanotube films, and comprises a rotating shaft and a rotating body; the rotating body rotates around the rotating shaft; the surface of the rotating body opposite to the rotating shaft is a bearing surface which is used for accommodating an object on which a film is to be spread; and the cutting device is used for cutting off the continuous carbon nanotube films. The invention also relates to a method for spreading films by using the film spreading system. By adopting the film spreading system and method, the carbon nanotube films can be continuously and uniformly spread, and the carbon nanotube film spreading efficiency and quality are improved.