The invention relates to railway fine tool machining auxiliary devices, in particular to a railway fine tool machining auxiliary clamp. The rail way fine tool machining auxiliary clamp comprises a base, a strip-shaped iron block, V-shaped grooves, fixing holes, pressing blocks, nuts, screw rods and positioning pins. The two positioning pins are arranged at the lower end of the base, and the strip-shaped iron block is connected to the upper end of the base. The four V-shaped grooves are formed in the strip-shaped iron block, and the strip-shaped iron block is provided with three isosceles trapezoid blocks in the middle and two non-isosceles right trapezoid blocks at the two ends. The middles of the upper ends of the two right trapezoid blocks and the middles of the upper ends of the isosceles trapezoid blocks are respectively provided with one fixing hole, and the upper ends of the other two isosceles trapezoid blocks are designed to be provided with the screw rods. The screw rods are sleeved with the pressing blocks, and the pressing blocks are provided with the nuts to be screwed on the screw rods. The railway fine tool machining auxiliary clamp has the advantages that the design is simple, using is convenient, fixing can be safely and effectively conducted, a plurality of fine tools can be machined at a time, the efficiency is improved, and cost is lowered.