Spring bolt assembly for lock

The invention provides a spring bolt assembly for a lock. The spring bolt assembly comprises a locking part, a spring bolt part, a spring bolt swing arm, a first elastic part and a second elastic part. A shifting wheel assembly of the lock comprises a first shifting wheel, a second shifting wheel and a shifting part. When the spring bolt part retracts inwards, the spring bolt part relieves positioning of the locking part, the locking part is inserted into a spring bolt groove, and the locking part abuts against a spring bolt frame of the spring bolt assembly so that the spring bolt frame can be positioned. The first shifting wheel or the second shifting wheel drives the locking part to move away from the spring bolt frame of the spring bolt assembly through the shifting part, the locking part is separated from the spring bolt groove, and the spring bolt swing arm pushes the spring bolt part to enable the spring bolt part to extend outwards. According to the scheme, when a door is closed, the spring bolt part