Thickness controllable porous polymer nanofilm with superior gas storage capacity has gradually emerged as promising adsorbents for capture of CO2, due to extremely high surface area and microscale pore. In this work, we have developed a novel and facile strategy to fabricate thickness controllable two or three dimensional ordered porous nanofilm based on poly(styrene-butyl acrylate), in combination with covalently layer by layer (LBL) self-assemble process and hypercrosslinked post-treatment. Abundant microporous structures and a small number of mesoporous structures are formed in hypercorsslinked nanofilm and corresponding surface area derived from Brunauer-Emmett-Teller method (BET) were determined to be 605.7 m(2)/g. The capacity of CO2 capture was also measured, which reach up to 53.6 wt% (12.2 mmol/g) at 273 K/1 bar, which is comparable to highest record. We have found that all the as prepared nanofilm with different thickness exhibited apparently enhanced micro- and mesoporosity after hypercrosslinking. Moreover, with the increase of thickness of nanofilm, the adsorption capacity decreases gradually, as well as the CO2 adsorption capacity. An excellent recycling capacity for CO2 capture have also found for this porous polymer nanofilm via repetitive adsorption-desorption assay. Our work confirmed that thickness controllable porous polymer nanofilm with superior CO2 capture capacity can be fabricated by a very simple strategy which can meet the challenges of the current CO2 capture and storage technology. (C) 2019 Elsevier Inc. All rights reserved.