Diesel engines have difficulty cold starting in severe cold environments. Pre-lubrication and preheating technologies are effective measures to address this issue. The present study examines the influence of the pre-lubrication measure, lubricant preheating temperatures, and oil gallery pre-fill fractions on diesel engines' low-temperature cold-start performance from lubrication and wear perspectives with flow simulations validated by bench tests. Results show that: 1) Between 0°C to −20°C of ambient temperature, while the pre-fill fraction of the main oil gallery increases to 80% by pre-lubrication, the dry friction wear of the bearings at the far end of the oil gallery decreases by more than 50.5%. 2) At −50°C of ambient temperature, dry friction ends in the early stage of engine startup if the lubricant is preheated to above 0° and the engine is pre-lubricated. The higher the oil temperature, the less the dry friction wear of bearings, but the wear amount barely decreases if the oil is preheated to above 40°C; 3) At −50°C of ambient temperature, pre-filling the main oil gallery to more than 80% significantly improved the bearing filling status. Increasing the main gallery pre-fill fraction from 20% to 100% can reduce the wear of bearings at the far ends by 56.8% to 85.4%. Considering both economy and performance, we recommend a cold-start strategy of preheating lubricant to 40°C and pre-filling the main oil gallery to 80% by pre-lubrication.