Polyether polyol (abbreviated as polyether) is an organic polymer, which is obtained by polyaddition reaction of initiator (compound containing active hydrogen group) with ethylene oxide (EO), propylene oxide (PO), butylene oxide (BO) etc. in the presence of catalyst. The largest polyether production is produced by using glycerol (glycerol) as initiator and epoxide (generally PO and EO are used together). By changing the feeding method of PO and EO (mixed or separate), feeding ratio, feeding order and other conditions, various general-purpose polyether polyols are produced.