A ball valve gasket structure includes a housing base having an accommodating area and a position limit area; a leakproof washer installed in the position limit area; a ring-shaped slide unit having a ring-shaped steel plate and a ring-shaped graphite plate installed in the accommodating area, and both top and bottom sides are ring-shaped steel plates of the slide unit, and the ring-shaped steel plate at the bottom side abuts the bottom of the accommodating area, and the other ring-shaped slide unit has an arc surface portion disposed at the internal periphery; and a cover coupled to the housing base for sealing the slide unit. The ball valve gasket structure can be used together with a ball valve to achieve the slide assisting effect, improving service life, and facilitating installation and disassembly.