FIELD: polymer production. SUBSTANCE: preparation method comprises following stages: (a) preparing mixture (a1) of at least one aromatic initiator containing at least two active hydrogen atoms in molecule, (a2) at least one polyethylene glycol with molecular weight 400-1000, and (a3) optionally one or several aliphatic initiators containing 2-6 active hydrogen atoms in amount up to 20 mol % based on the summary number of (a1) and (a3) moles at (a1)/(a3) molar ratio between 0.5:1 and 5:1; (b) interaction of mixture obtained in stage (a1) in presence of suitable alkoxylation catalyst with at least one alkylene oxide having three or more carbon atoms in such an amount as to obtain polyether- polyol with hydroxyl number 150 to 400 mg KOH/g; and (c) isolating jointly initiated polyetherpolyol. EFFECT: enabled preparation polyether-polyol appropriated for manufacture of inflexible polyurethane foams avoiding use of any polyesterpolyol. 10 cl, 1 tbl, 3 ex
