The invention provides a gas well intelligent plunger drainage device and a construction method. The gas well intelligent plunger drainage device comprises a fishing head, an upper elastic block, an upper connecting cylinder, a lower elastic block, a lower connecting cylinder and a liquid nitrogen storage cylinder which are mounted from top to bottom in sequence. The lower part of the fishing headand the upper part of the upper connecting cylinder are connected respectively with upper and lower ends of an upper elastic block base through pins. A plurality of upper springs are mounted betweenthe upper elastic block and the upper elastic block base through spring pins. The lower part of the upper connecting cylinder and the upper part of the lower connecting cylinder are connected respectively with upper and lower ends of a lower elastic block base. A plurality of lower springs are mounted between the lower spring block and the lower spring block base through spring pins. A nitrogen nozzle is arranged at the bottom end of the lower connecting cylinder. The outer wall of the liquid nitrogen storage cylinder is closely attached to the inner walls of the upper elastic block base, theupper connecting cylinder, the lower elastic block base and the lower connecting cylinder. The liquid nitrogen storage cylinder is equipped with a check valve at the top and an adjustable switching device at the bottom. According to the invention, the ejecting of liquid nitrogen is controlled to improve the drainage capability of the plunger so that the stable production of the gas well can be achieved.