The invention discloses a method for machining bearing block parts with precision dimensions. The method is characterized in that an independent important diameter dimension fine turning procedure is added after all machining procedures are completed; the flatness of a reference plane for the parts, the flatness of a disc chuck of a machine tool and the flatness of a fixture positioning surface are controlled, and process control on the coloring contiguity of the reference plane for the parts is strengthened; the disc chuck and a fixture surface of the machine tool are trimmed, so that the flatness of the fixture positioning surface can be guaranteed, the fitting degree between the machining reference plane for the parts and the fixture positioning surface is higher than 75%, and suspension of compressed positions is prevented. The method mainly includes rough lathing, stabilizing treatment, finish lathing, corrosion, boss plane milling, through hole linear cutting, semi-fine turning, planar groove electric sparkle treatment, fine turning, hole boring and elongated slot milling, inner plane and disc edge milling, plane and hole milling, inclined hole drilling, tapping, grinding, inner hole fine turning, fluorescence treatment and inspection. The method has the advantages that deformation of the aviation and aerospace bearing block parts with the precision dimensions in machining procedures can be effectively controlled, and the method is wide in application range and prospect.