The disclosure discloses a trimmer head and a grass trimmer. The trimmer head includes a spool formed with a winding portion for winding a trimmer line； a head housing formed with an accommodating space for accommodating at least a portion of the spool. The trimmer head further comprises an intermediate element for transmitting a torque between the spool and the head housing such that one of the spool and the head housing rotates with the other, the spool drives the intermediate element to rotate, the intermediate element is slidably connected to the spool in a direction along a rotation axis or parallel to the rotation axis. The spool does not move in the axial direction when the trimmer head of the grass trimmer is playing the trimmer line, thereby effectively avoiding the problem of the trimmer line jamming.
