The invention discloses energy-saving engineering machinery hydraulic oil with a high viscosity index and an ultralow temperature. The energy-saving engineering machinery hydraulic oil is composed of, by weight, 0.1-1 part of tricresyl phosphate, 0.5-1.5 parts of an antiwear agent, 3-7 parts of benzene triazole fatty amine, 1-5 parts of ethylene glycol oleate, 70-90 parts of viscosity index improvers, 1-3 parts of purification dispersant, 1-3 parts of antioxygen, 2-4 parts of 4, 4'-di-iso-octyldiphenylamine, 3-9 parts of pour point depressant, 0.01-0.05 part of an anti-foaming agent and 800-1000 parts of base oil. According to the energy-saving engineering machinery hydraulic oil, an ash-free extreme pressure antiwear additive agent is adopted for complex formulation, applicability is wider, abrasion resistance is better, efficiency is higher, and lubrication of a plunger pump of a hydraulic transmission system with high power and high pressure can be effectively met; preferably, compatibility between an oiliness agent and the antiwear agent with the base oil is good, and lubrication guarantee can be provided in time in different work stages; equipment can operate steadily, pressure transfer is even, frication is lowered, abrasion is reduced, temperature rise is low, heat dissipation is high in speed, the power loss is lowered, energy consumption is saved, and the oil exchange cycle is prolonged.