A ball valve assembly comprising a main body, a secondary body, seals, and a sealing enclosure device. The main body and the secondary body are fixedly connected, with the main body having one cavity and the secondary body having two cavities. The seals are fixed between the main and secondary bodies. The rear end of the sealing enclosure device is mounted on the seals, isolating the two cavities through the sealing enclosure device. The secondary body features an inlet and an outlet, both connected to the two cavities. The sealing enclosure device includes a storage cavity that is in communication with the two cavities.