Abstract: The present invention provides a multifunctional biological substance separation device or dehydration device illustratively comprising a housing, a spindle push rod running through the housing, a return device, a magnetic sleeve connecting ring, and an electric actuator. An end of the spindle push rod is provided with a magnetic column. The magnetic sleeve connecting ring is provided on the spindle push rod in a sleeving manner and one end, which is positioned outside the housing, of the connecting ring is provided with a magnetic sleeve. The return device is provided in the housing and is used for enabling the spindle push rod to move in a direction away from the magnetic sleeve. The electric actuator is connected to the connecting ring and is used for enabling the connecting ring (and the magnetic sleeve provided thereon) to rotate.