A compensating mechanism includes a base, an adjusting unit, an adjusting cap and a stop unit. The adjusting unit is disposed on the base. The adjusting cap is configured to move the adjusting unit with respect to the base so as to form a first circumferential movement range. The stop unit includes a sliding element and a limiting element, wherein the limiting element includes a movement region, and the adjusting cap is configured to move the sliding element along the movement region so as to form a second circumferential movement range. A sum of a first central angle corresponding to the first circumferential movement range and a second central angle corresponding to the second circumferential movement range is a fixed value. The invention also provides a sight, wherein the sight includes a main body, an objective unit, an ocular unit, an inner lens barrel and the compensating mechanism.