Bar polygon and special-shape machining method and machining method thereof

The invention discloses a bar polygon and special-shape machining method. The bar polygon and special-shape machining method comprises the following steps that S1, a blank bar is clamped and fixed; S2, the position of a V block of a pressing wheel V block mechanism is adjusted and fixed; S3, a Y-axis feed mechanism is moved, the bar is made to penetrate the V block, and a pressing wheel of the pressing wheel V block mechanism is pressed; S4, a Z-axis feed mechanism is moved, and the Y-axis feed mechanism, a work head of a main shaft head mechanism and a V block support mechanism are together fed to a grinding start position; S5, according to the set polygon or special-shape first grinding track, the Z-axis feed mechanism, a C-axis mechanism, an X-axis coarse grinding mechanism and a V-axisfine grinding mechanism are used for grinding adopting interpolation; S6, the X-axis coarse grinding mechanism, the V-axis fine grinding mechanism and the Z-axis feed mechanism are sent back to the start grinding position; a