The present disclosure provides a flow regulator capable of regulating flow resistance of a fluid by adjusting helical pitch of the flow regulator. The flow regulator comprises: a channel, a rod, and a helical coil. The channel has a fluid inlet and a fluid outlet for a fluid flowing in and out of the flow regulator, respectively. The rod has a fore end and a rear end opposite to each other. The fore end is inside the channel, and the rear end is closer to the fluid outlet than the fluid inlet. The helical coil winds around the rod, and the helical pitch of the helical coil is adjustable for regulating flow resistance of the fluid. The channel further has a narrowed section where part of the helical coil located therein substantially occupies an annular space between the rod and an inner wall of the channel.