Porous support, preparation method therefor, and reinforced membrane containing same

A method of manufacturing a porous support comprising:

• spinning a spinning solution to form a nanoweb precursor which includes in which nanofibers are integrated in the form of a non-woven fabric including a plurality of pores;
• and
• curing the nanoweb precursor while transferring the nanoweb precursor by a roll-to-roll method under the condition that a MD tension is equal to a TD tension,
• wherein the nanoweb has a strain of 10 length % or less, said strain being determined by standing a sample of the nanoweb with a width 100 mm and a length of 100 mm at 200° C. for 24 hours and calculating an average of width strain and length strain, before and after standing, and
• wherein the nanoweb has an intermediate elongation of 0.7 to 5% under a load of 10.204 gf.