Disclosed are a backlight module and a curved display device. The backlight module includes a backplane and a backlight. The backplane includes a backplane body and two arc fixing components. The backplane body is provided with two opposite arc sides and each arc fixing component is correspondingly detachably installed at each arc side to restrict a curvature of the backplane body. A mounting groove is formed by the cooperative enclosure of two arc fixing components and an inner surface of the backplane body. The backlight is provided into the mounting groove.