The invention discloses a laser grooving machining method of a dry gas seal spiral groove, wherein a machining device is a 20W optical fiber marking machine. The machining method comprises the following steps of: (1) designing the shape of the dry gas seal spiral groove by special drawing software; (2) positioning, wherein a ring with outer diameter being is less than or equal to 100mm is positioned in a marking range, and a ring with outer diameter being more than 100mm is positioned by a groove-to-groove machining method; and (3) grooving which is implemented by selecting appropriate marking parameters of focal length, marking speed, effective vector step length, power, frequency and the like. The laser grooving method has the characteristics of having a wide application range, being applicable to machining surfaces of different materials and different shapes, ensuring no mechanical deformation of workpieces, no pollution, high speed, high accuracy, good repeatability, high automation degree, and the like, is used for machining logarithm spiral grooves, rectangular grooves and dual-trapezoid grooves, is especially suitable for machining shallow grooves, and has obvious effects of improving product quality and machining efficiency.