The invention discloses an open gear lubricant combination which comprises high-viscosity synthetic base oil, synthetic ester base oil and an additive having a weight ratio of (55-93):(5-25):(2-20). Because the high-viscosity synthetic base oil has the characteristics of high viscosity index, better high-temperature and low-temperature performance and lower friction coefficient, and the synthetic ester base oil has the characteristics of low pour point and excellent solubility and perceptibility of the additive, the high-viscosity synthetic base oil and the synthetic ester base oil are matched in the invention, and a proper amount of additive is added, thus ensuring that the lubricant combination has the following characteristics: the lubricant combination has higher viscosity and excellent viscosity-temperature performance, and is beneficial to formation and maintenance of a lubricant film in the process of using oil products; under the condition of the same viscosity range, the open gear lubricant has excellent low-temperature flowing performance, thereby enlarging in use temperature range; and in use, the low-fluid friction of a gear pair in a load region can be caused, the operation temperatures of a gear and a gear transmission device are lowered, and the efficiency of the gear is increased.