Flexible printed circuit board and display device

Provided are a flexible printed circuit board and a display device. The flexible printed circuit board comprises a main flexible printed circuit board and a connection flexible printed circuit board having different outlines. Both printed circuit boards are single-layer boards or double-layer boards. The main flexible printed circuit board comprises a bonding region, a device mounting region, a first connection region and signal lines. The signal lines include a first signal line positioned between the device mounting region and the first connection region, and a second signal line positioned between the device mounting region and the bonding region. The connection flexible printed circuit board comprises a second connection region, a third connection region and a third signal line positioned between the second connection region and the third connection region. The two flexible printed circuit boards are connected by means of the first connection region and the second connection region. An orthographic projection of the third signal line on the main flexible printed circuit board overlaps with the second signal line. In an overlapping region, an electromagnetic shielding structure is at least provided at one side of the main flexible printed circuit board facing the connection flexible printed circuit board or at one side of the connection flexible printed circuit board facing the main flexible printed circuit board.