Cast-in-situ bored pile concrete surface elevation device and method

The invention discloses a cast-in-situ bored pile concrete surface elevation device and method. The cast-in-situ bored pile concrete surface elevation device comprises a pile casing installed in a deep hole, an automatic rotation device, a measuring rope and a hanging ball, wherein the automatic rotation device, the measuring rope and the hanging ball are installed on the pile casing; the pile casing is located at the top of the deep hole, and part of the pile casing stretches out of the deep hole; the depth of the deep hole is not smaller than 10m; the measuring rope is provided with a plurality of scales; one end of the measuring rope is connected with the automatic rotation device, and the other end of the measuring rope is connected with the hanging ball; in the lifting process of the hanging ball in the deep hole, the gravity of the hanging ball is G, and the automatic rotation device generates tension F to the hanging ball all the time through the measuring rope; and the tension F is smaller than G all