FIELD: petroleum extracting industry. SUBSTANCE: composition is used for dehydration and desalting of petroleum and simultaneously protection it from hydrogen sulfide and microbiological corrosion. Composition comprises, wt %: glycol or glycerol-based ethylene- propylene oxide block copolymer with molecular weight of 5000-6400, 48-52; 25% aqueous glytamic aldehyde solution, 10-15; and methanol, the balance. Protective effect from hydrogen sulfide corrosion is 65-92% at composition concentration of 30-100 g/m of petroleum and degree of biocenosis suppression is 80-100% at composition concentration of 50-150 g/cubic m. EFFECT: high emulsifying effect of the composition and high protection thereof from corrosion. 14 ex, 3 tbl
