A magnetic coupling assembly for a magnetic stirrer includes a non-magnetic disc embedded with two or more pairs of magnets. The two magnets of each pair are oriented with opposite magnetic poles pointing in the upward direction. When the magnetic coupling assembly is driven to rotate, it can bind one or more axially magnetized stir bar in a mixer at a relatively higher speed to achieve better mixing result without causing spin-out or jumping-flea phenomena, compared to when only one pair of magnets is used.