A child safety seat includes: a base provided with a pivotable support leg; a seat having a backrest, the backrest being provided with a height-adjustable headrest; a headrest limiting device operably connected to the support leg and including a first locking member, when the support leg is in an unfolded state, the first locking member is in an extended state, so that the first locking member is capable of being engaged with the headrest, thereby limiting an upper adjustment height of the headrest, and when the support leg is in a folded state, the first locking member is in a retracted state; or a second locking member, when the support leg is in the unfolded state, the second locking member is in a retracted, and when the support leg is in the folded state, the second locking member is in an extended state, so that the second locking member is capable of being engaged with the headrest, thereby limiting a lower adjustment height of the headrest.