A magnetic separation device, comprising: at least a test tube base, for receiving at least a test tube; and a magnetic member, pivotally connected to the at least one test tube base and capable of generating a magnetic force. With the aforesaid device, the test tube being received in the test tube base can be moved toward/away from the magnetic member while the magnetic member and the test tube base are driven to rotate about a pivotal end connecting the two, and thereby, the strength of the magnetic force applied on a mixture containing in the test tube by the magnetic member is varied accordingly.