This application discloses a rotatable child seat mounting base and a
child restraint system. The child seat mounting base includes: a connecting frame; a rotating disk rotatably mounted on the connecting frame; a first
locking mechanism and a second
locking mechanism mounted on the rotating disk, the first
locking mechanism providing a first locking groove and a second locking groove, and the second locking mechanism providing a third locking groove and a fourth locking groove, each locking groove opening upwards in the direction of gravity and equipped with a corresponding locking hook; and a drive arm rotatably mounted on the rotating disk, with both ends of the drive arm linked to the first locking mechanism and the second locking mechanism respectively. The drive arm has a working position that drives each locking hook to open its corresponding locking groove and a standby position. In the standby position, each locking hook closes its corresponding locking groove. During the rotation of the rotating disk, the first locking mechanism, the second locking mechanism, and the drive arm move with the rotating disk. This application achieves a highly stable locking effect, a
simple component fit relationship, and a rich design basis to improve the user experience.