Disclosed is a cleaning device (400), comprising a support (450) and a bearing assembly (410) provided on the support (450), a magnetic attraction assembly (420), a liquid injection assembly (430) and a liquid absorbing assembly (440), wherein the bearing assembly (410) is provided on the support (450) and can make a reciprocating movement between a first station (401) and a second station (402), the bearing assembly (410) is provided with at least one cleaning station (412), and the cleaning station (412) is used for placing a reactor (20); the magnetic attraction assembly (420) is provided near the second station (402) and is used for absorbing a magnetic particle conjugate (21); the liquid injection assembly (430) comprises a liquid injection member (431), and the liquid injection member (431) is used for injecting a cleaning fluid in the reactor (20) located at the first station (401); the liquid absorbing assembly (440) comprises a liquid absorbing member (441) which can correspond to the cleaning station (412) on a one-to-one basis, and the liquid absorbing member (441) is used for absorbing waste liquid in the reactor (20) located at the second station (402); and the same reactor (20) absorbs waste liquid by means of the same liquid absorbing member (441).