Ultralow-temperature diesel engine oil

The invention belongs to the technical field of research and development of lubricating oil, and particularly relates to ultralow-temperature diesel engine oil. The ultralow-temperature diesel engine oil is characterized by being prepared from the following components in parts by weight: 20 to 22 parts of PAO 4 base oil, 51 to 55 parts of PAO 6 base oil, 5 parts of ester base oil, 15.1 parts of a composite additive, 0.45 part of an adjuvant and 6.0 to 6.5 parts of a tackifier. The ultralow-temperature diesel engine oil disclosed by the invention is compounded by adopting the high-quality base oil and the additive, the tipping point of an oil product is low and is up to -60 DEG C, and the use in all regions of China in winter can be met; the ultralow-temperature diesel engine oil can meet 0W-30 viscosity grade requirements; the ultralow-temperature diesel engine oil can meet the quality grade requirements of API (American Petroleum Institute) CI-4. 本发明属于润滑油研发技术领域，特别涉及种超低温柴油机油。种超低温柴油机油，其特征在于，由按重量份的以下组分组成：PAO 4基