An electronic device and a connector thereof are provided. The electronic device includes a circuit board and an electronic device and the connector disposed on the circuit board. The connector includes a slot and a cap. The slot is configured for a card module to be plugged in along a plugging direction. A first pillar portion and a second pillar portion are at two opposite sides of the slot. The cap is disposed on a top of the first pillar portion and has a first protruding portion. The first protruding portion protrudes out of a side of the first pillar portion away from the second pillar portion while observing along the plugging direction.