NOVELTY - A multi-level series-wound marsh gas grade lifting system comprises several polyethylene sealing bags connected in series to form multi-stage reactor, each bag contains reactor (1), top part is provided with air outlet (2), outlet of interface is connected in series through pipe, pipeline is provided with air valve (3), air outlet in the reactor, a biogas reactor for culturing microalgae nutrient matrix by biogas liquid, and marsh gas of carbon dioxide enters gradually into reactor after stopping for certain time in upper reactor by micro-algae.    USE - As multi-level series-wound marsh gas grade lifting system (claimed).    ADVANTAGE - The system significantly improve the quality of gas pollutants, while the high load there is a certain biogas purification. The system is simple, easy to operate and has good economic advantages. The microalgae culture liquid nutrient matrix is fermented biogas slurry, which not only can save the cost of culture medium and capable of purifying biogas slurry. The reactor is transparent, light and easy to use, has low cost, and is convenient to install and move.    DETAILED DESCRIPTION - A multi-level series-wound marsh gas grade lifting system comprises several polyethylene sealing bags connected in series to form multi-stage reactor, each bag contains reactor (1), top part is provided with air outlet (2), outlet of interface is connected in series through pipe, pipeline is provided with air valve (3), air outlet in reactor, a biogas reactor for culturing microalgae nutrient matrix by biogas liquid, marsh gas of carbon dioxide enters gradually into a reactor after stopping for certain time in upper reactor by micro-algae. The liquid nutrient matrix is fermented biogas slurry. The reactor is transparent polyethylene sealing bag. The system further comprises a checking port (4) according to the upper part of the reactor; and solid oxygen adsorbent (6) set to the last level reactor outlet. The reactor is provided with a micro-algae culture LED light source (5), micro-algae culture process, single light source subassembly of LED street lamp using LED as artificial light source, or using natural light and LED light source combined with the upper flange.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of series-wound marsh gas grade lifting system device.    Reactor (1)    Air outlet (2)    Air valve (3)    Checking opening (4)    Light emitting diode (LED) light source (5)    Solid oxygen adsorbent (6)