The multistage pulsating airlift pump includes a lowermost air injector stage and at least air injector stage above the lowermost stage installed in a lift pipe. Each stage includes a multifunction timer. The stages above the lowermost stage have sensors along the lift pipe communicating with the respective timers of those stages. The timers are adjusted to provide time delays in accordance with a number of parameters, e.g., the height of the pipe, pressure head, etc. When a sensor detects a rising gas slug, the sensor sends a signal to its timer to start an elapsed delay time. When the delay time has elapsed, the timer opens a control valve to send another volume of gas into the injector in the pipe. The sequentially spaced series of gas slugs rising in the pipe provide constant lifting for the liquid to a much greater height than using a single-stage airlift pump.