The invention discloses composite synthetic
air compressor oil comprising the following components: a
promoter, diisoalkyl (C8 to C13) linear
dibasic ester, poly-alpha-olefin
synthetic oil and diisoalkyl (C8 to C13)
phthalate esters, wherein, the composite synthetic
air compressor oil contains 15% to 20% of diisoalkyl (C8 to C13) linear
dibasic ester by weight, 5% to 10% of poly-alpha-olefin
synthetic oil by weight and 72% to 74% of diisoalkyl (C8 to C13)
phthalate esters by weight. The composite synthetic
air compressor oil of the invention can meet the requirements that the carbon residue value thereof is low and the
biodegradation rate is higher than 70%; the composite synthetic air compressor oil has high high-temperature anti-
oxidation stability, lubricating properties,
rust-preventing properties, foam resistance and
emulsion resistance; and the invention has the advantages that the energy is saved, the environmental
pollution is reduced and the service life is prolonged, therefore, the invention can fully satisfy the operating requirements for rotary-type screw compressors.