The invention provides a gas-liquid two-phase fluid double-layer pipeline transportation tail end net type foaming device which comprises a double-layer pipeline. The double-layer pipeline comprises an outer layer pipe and an inner layer pipe; the inner layer pipe and the outer layer pipe are connected through a connecting rod and form an annular cavity; the inner layer pipe is used for conveyingfoaming agent premixed liquid, and the annular cavity is used for conveying gas; the output end of the inner layer pipe is provided with an atomizing nozzle; and the outer layer pipe is provided witha foaming net in the spraying direction of the atomizing nozzle. The atomizing nozzle is used for atomizing the premixed liquid containing the foaming agent into fine particles and spraying the fine particles onto the foaming net, the foaming net has high adsorption force on the atomized particles, the atomized particles attached to the foaming net are foamed under the action of high-pressure gasconveyed through the annular cavity between the inner layer pipe and the outer layer pipe, and the atomized particles are injected into a target area. The defects that the resistance loss along the path of a downstream foam conveying pipeline is large, the pressure at the outlet of the tail end of the pipeline is small, the foam is likely to break, the final foaming effect is poor and the like when a traditional device is used for treating a high-level fire area are overcome.