The invention discloses a 1/2 bowl sphere combination looseness regulator, which comprises a pair of connecting rods, a pair of under-semi-cylindrical adjustable clamping blocks and at least one lantern ring, wherein one end of each connecting rod is provided with a buckle, and the other end of each connecting rod is provided with a bowl sphere; a plurality of semi-bowl sphere seats are arranged in each under-semi-cylindrical adjustable clamping block at intervals, the corresponding semi-bowl sphere seats on the pair of under-semi-cylinderical adjustable clamping blocks form a bowl sphere seat for accommodating the bowl sphere, and at least one groove which extends along the peripheral direction of the outer surface of the under-semi-cylindrical adjustable clamping block is arranged on the outer surface of at least one under-semi-cylindrical adjustable clamping block; and the lantern ring is used for clamping the pair of under-semi-cylindrical clamping blocks, the internal diameter of the lantern ring is larger than the maximum external diameter after the pair of under-semi-cylindrical clamping blocks are tightly combined, and at least one part of the lantern ring is placed in the groove. The 1/2 bowl sphere combination looseness regulator is combined by only adopting four kinds of parts, has a simple structure, and is quick and convenient to assemble.