An angle-adjustable exerciser comprises a base, an adjustment disk set and a support plate. The base attaches to a spherical cast piece on top and a plate with large surface at bottom. At the periphery of the spherical cast piece, there is an adjustment disk set composed of the first disk, the second disk and a few screws. At center of the first and second disks, there are holes for the disks to install at the periphery of the cast piece. At the corresponding position, there are several through holes at the first and second disks, so the disks can be connected by at least two positioning screws. The distance between the disks is maintained by positioning screws. Another through hole is for an adjustable screw to tighten or loosen the disks. This is also to adjust the declined angle for the adjustment disk set on the spherical cast piece.