The invention discloses a throttle valve for downhole liquid level control. The throttle valve comprises a valve body, a valve element, an adjusting bolt, a compression spring, a seal ring and a limiting gasket. A valve element hole is processed in the valve body radially. The valve element is of a slide valve structure, and an oil groove, a seal ring groove and a reinjection water groove are processed in the valve element. A reinjection water channel and a gas generation channel are processed on the valve body radially. The adjusting bolt can adjust acting force of the compression spring. A through hole processed in the limiting gasket is communicated with the external annular space of the valve body and the right end of the valve element. The throttle valve simple in structure and convenient to connect is used for downhole liquid level control of a drainage gas recovery well to prevent pump burning caused by dry grinding of a reinjection pump.