The invention relates to a driving mechanism and method for a furniture assembly. The furniture assembly comprises a first furniture piece and a second furniture piece, the second furniture piece can conduct movable displacement relative to the first furniture piece, and the driving mechanism comprises a driving device, a locking device and an oscillating piece. The driving device comprises an elastic piece. The locking device comprises a locking part and a guide piece, and the guide piece generates force to the locking part; the oscillating piece is movably connected to the second furniture piece, and is operably clamped between the locking part and the guide piece, so that the elastic piece of the driving device keeps driving force; when the oscillating piece is removed from being clamped between the locking part and the guide piece, the driving force is released to drive the second furniture piece to conduct displacement relative to the first furniture piece from a retracting position to a starting position.