The invention relates to an 
alternating current electric 
transmission line lightning flashover restriction method and device. The method includes the steps of current steering, 
voltage limiting and arc blowing-out. The current steering includes the steps of providing a current 
discharge channel for 
power frequency short-circuit current through a parallel gap, wherein the parallel gap is mounted on both ends of an insulator, the 
breakdown strength of the parallel gap is lower than that of the insulator, and 
lightning current flows through the parallel gap rather than passing through the insulator when the parallel gap is broken down by 
lightning. The 
voltage limiting includes the steps of connecting a non-linear 
energy absorbing assembly in series with the parallel gap and limiting over-
voltage at both ends of the insulator to prevent the insulator from being damaged by lightning flashover, wherein the non-linear 
energy absorbing assembly is used for absorbing lightning current energy on the basis of current steering. The arc blowing-out includes the steps of treating continuous 
combustion caused by arc produced in the parallel gap when the 
power frequency short-circuit current continues to flow through the parallel gap after lightning current passes to prevent 
tripping of a 
circuit breaker. The 
alternating current electric 
transmission line lightning flashover restriction device is composed of the parallel gap, electrodes, the non-linear 
energy absorbing assembly and a special-shaped connecting unit which are assembled and connected with one another and is simple in structure, light in weight and small in size.