Ionic liquids have been found abroad application as lubricant additives due to their unique physic properties, as well as the powerful friction-reducing and anti-wear performances. In this work, four examples of 1,8-diazabicyclo[5.4.0]undecane-7-ene-organophosphoric acid-based protic ionic liquids were synthesized via simple neutralization and valuated as lubricant additives in PAO-10. These unique ionic liquids with dianionic and dicationic structure in one molecular could achieve maximum decreases by 60% in the friction coefficient and 83% in wear volume. After a series of tests including contact angle, ECR, SEM, EDS, and XPS, it was confirmed that the physical adsorption film and chemical reaction film generated during the friction process were responsible for the excellent tribiological performances. Besides the simple synthesis and exceptional tribological abilities, convenient purification procedure and low cost together make this powerful type of ionic liquid additives great potential to be employed in the industrial field.