The invention discloses an underground gas lift valve which comprises a shell. An adjusting cavity, a gas inlet cavity and a transition cavity are formed in the shell. A gas bag is installed in the adjusting cavity which is communicated with the gas inlet cavity through a vent hole. The gas inlet cavity is communicated with the transition cavity through a small hole. Communication holes are formedin the two sides of the gas inlet cavity. A top rod is arranged in the middle of the gas inlet cavity. The vertical section of the top rod is sleeved with a return spring. The top of the vertical section of the top rod penetrates through the vent hole and extends upward to be connected with the bottom of the gas bag. A first ball body is arranged at the bottom of the horizontal section of the toprod. A gasket is arranged on the inner wall of the gas inlet cavity. A seal hole coaxial with the small hole is formed in the middle of the gasket. In order to solve the problem that during gas liftoil production in the prior art, the adjustment of high-pressure gas flow is not accurate and oil production efficiency is reduced, by arranging the different cavities, the linkage control over high-pressure gas flow is conducted, high-pressure gas flow flows more smoothly between a sleeve and an oil pipe, adjustment is more precise, and the gas-lift oil production efficiency is improved.