Tooth end modification has a great effect on minimizing the meshing impact of double-arc gears, reducing vibration and noise during transmission, and enhancing the service life of gears. This paper investigates the impact of tooth end modification on the lubrication status of the tooth surface of double-arc gears. Based on the meshing characteristics and the principle of tooth end modification of double-arc gears, tooth end modification is conducted, and the amount of tooth end thinning and the modification length are determined. By calculating the contact force changes in accordance with the meshing law and Hertz contact deformation theory of double-arc gears and combining it with the elastohydrodynamic lubrication theory, the influence of tooth end modification on tooth surface pressure, oil film thickness, and temperature rise is analyzed. The results indicate that end-milling modification reduces the engagement impact while altering the instantaneous number of contact points on the tooth surface. It increases the pressure at certain contact points on the tooth surface, raises the temperature of the tooth surface, and decreases the oil film thickness. Therefore, double-arc gears with end-milling modification should be designed carefully to mitigate the impact of end-milling on the lubrication characteristics of the tooth surface.