A dumbbell facilitating weight adjustment is disclosed. The dumbbell includes a dumbbell rod assembly, multiple counterweight disks, and a base for placing the dumbbell rod assembly and the multiple counterweight disks. The dumbbell rod assembly includes a mandrel, fixed disks and gear rotating disks fixed on the left and right sides of the mandrel, positioning rings and multiple coupling flanges. Rotation interference devices for preventing a rotation of the mandrel are provided in the fixed disks. Unlocking devices for unlocking the rotation interference devices are provided on the base. The rotation interference devices include push rods arranged on front sides and rear sides of the positioning rings, pressing rods arranged on upper parts of the push rods and return springs arranged on upper parts of the pressing rods. The unlocking devices include push pillars arranged on the base and cooperating with the push rods.