The invention discloses a lubrication and oil distribution device for a high-speed gearbox. The device comprises an oil distribution box body internally provided with an upper cavity and a lower cavity. A pressure adjusting plate with pressure adjusting holes is arranged between the upper cavity and the lower cavity in a spaced mode. The oil distribution box body is provided with an oil inlet communicating with the lower cavity and further provided with multiple lower cavity oil outlets communicating with the lower cavity respectively and upper cavity oil outlets communicating with the upper cavity. The diameter and number of the pressure adjusting holes in the pressure adjusting plate can be determined according to the size of the oil inlet, the lower cavity oil outlets and the upper cavity oil outlets and needed lubrication oil pressure. Lubrication oil enters the lower cavity through the oil inlet, the lower cavity is filled with one part of lubrication oil, the other part of lubrication oil enters the upper cavity through the pressure adjusting holes in the pressure adjusting plate, two kinds of different pressure lubrication oil are formed in the lower cavity and the upper cavity, and the lubrication oil is connected with a sliding bearing lubrication oil channel through the lower cavity oil outlets for lubricating a sliding bearing and connected with a gear lubrication oil channel through the upper cavity oil outlets for lubricating a gear.