The invention belongs to the technical field of the coal-bed gas well completion process and provides an intermediate casing recovering and connecting device passing through a mined-out region and a recovery process in order to recover an intermediate casing installed in the mined-out region. The intermediate casing recovering and connecting device comprises a connecting and recovering device body A and a connecting and recovering device body B. The connecting and recovering device body A comprises a big-diameter section and a small-diameter section which are in transition connection through a body A, wherein an internal thread of the big-diameter section is a right-handed female thread, and an external thread of the small-diameter section is a left-handed male thread. The connecting and recovering device body B comprises a big-diameter section and a small-diameter section which are in transition connection through a body B, wherein an internal thread of the big-diameter section is a left-handed female thread, and an external thread of the small-diameter section is a right-handed male thread. The left-handed male thread is matched with the left-handed female thread. After a well completion pressure test is passed, the casing is rotated clockwise and continuously meshed with the right-handed thread of the connecting and recovering device body A, the left-handed thread of the connecting and recovering device body A and the left-handed thread of the connecting and recovering device body B are unscrewed, and the casing as a free section is taken out; the material expenses of the single well casing is reduced, and obstacles are cleared for subsequent coal mining.