Downhole gas-liquid separation lifting device and method

The invention discloses an underground gas-liquid separation lifting device and method. The underground gas-liquid separation lifting device comprises an outer cylinder, a pump cylinder, a plunger and a packer. The pump cylinder is sleeved with the outer cylinder, a first annular space is formed between the inner wall of the outer cylinder and the outer wall of the pump cylinder, a second annular space is formed between the outer wall of the outer cylinder and the inner wall of the sleeve, and the upper end of the first annular space communicates with the second annular space; the packer is connected to the lower end of the outer cylinder and arranged on the inner wall of the casing pipe in a setting mode, namely the lower end opening of the second annular space is blocked by the packer. The plunger axially runs in the pump cylinder, the pump cylinder and the outer cylinder are connected with a radial gap bridge channel at the same time, the gap bridge channel serves as a fluid inlet pump channel, the inner e