The invention discloses an auxiliary machining mechanism for front axle plate spring holes, and relates to an auxiliary machining mechanism for automobile parts. The auxiliary machining mechanism comprises two automatic angle adjusting mechanisms, a two-side centering adjusting mechanism, two adjustable supporting and pressing mechanisms, and a base, wherein the two automatic angle adjusting mechanisms and the two adjustable supporting and pressing mechanisms are symmetrically arranged on the base, and the two-side centering adjusting mechanism is connected to the position between the two automatic angle adjusting mechanisms. According to the auxiliary machining mechanism, main pin positioning seats of the automatic angle adjusting mechanisms rotate around supporting shafts within the range limited by limiting screws, thus, the positioning and supporting angle of a workpiece can be automatically adjusted, the main pin positioning seats located at the two ends can move to the appropriate length positions in a centering mode through the two-side centering adjusting mechanism, the workpiece is reliably supported and pressed through the adjustable supporting and pressing mechanisms, and accordingly, quick and accurate positioning of the workpiece can be achieved; and moreover, the auxiliary machining mechanism has the characteristics of being suitable for batch production, capable of improving the production efficiency and relieving the operation intensity of workers, and wide in application range, and is easy to apply and popularize.