The invention relates to a gas lift well liquid drainage simulation test device and a testing method and belongs to the technical field of oil and gas field gas lift well liquid drainage. The gas lift well liquid drainage simulation test device comprises a shaft simulation system, a liquid supplying system, an air supplying system and a temperature pressure control device. In the gas lift well liquid drainage simulation testing method, testing parameters of the liquid drainage test device are set according to a practical production well condition, and a gas lift well liquid drainage simulation test device is built; testing parameters of the liquid drainage simulation test device are adjusted according to an operation condition of the liquid drainage simulation test device; and practical operation parameters of the practical production well are determined. The beneficial effects are that based on open and close work conditions of a gas lift valve in the shaft simulation system, a process of a liquid level in the shaft simulation system decreasing with the gas lift valve work condition step by step is observed and operation parameters of the gas lift valve in the shaft simulation system are adjusted; and operation parameters of the gas lift valve in the practical production well are determined, so the gas lift valve can remain an optimal state and accumulated liquid in the shaft can be discharged step by step.