The invention relates to a ball valve special for feeding of a powder reaction still. The ball valve comprises a valve body, a valve element, a valve rod, a left sealing ring and a right sealing ring.The valve body comprises a reaction still connecting end and a flange connecting end, and the left sealing ring is fixedly arranged at the reaction still connecting end. The ball valve further comprises a limiting sleeve, a connecting flange, a cover plate and a clamp. One side of the limiting sleeve stretches into the flange connecting end. The right sealing ring is fixedly arranged on the limiting sleeve. One end of the connecting flange is detachably connected with the valve body, and the connecting flange is used for limiting the limiting sleeve. The cover plate and the clamp cooperate sothat the cover plate can close the other end of the connecting flange. During use, the cover plate is opened, the valve element is rotated, so that materials enter the reaction still through the ballvalve special for feeding of the powder reaction still. During cleaning, the connecting flange is demounted, the limiting sleeve is taken out, and the valve element can be taken out from the flange connecting end.