The invention relates to a damping regulating valve for a shock absorber. The damping regulating valve mainly comprises piston rods, limiting blocks, a valve plate group, a piston, springs, spring positioning seats, a fastening nut, a throttle valve core, sealing rings and the like. The valve can be applied to single-cylinder shock absorbers and double-cylinder shock absorbers. The throttle valvecore installed in the piston automatically senses road surface vibration and automatically switches to a suitable damping value. The damping characteristic of the shock absorber equipped with the damping regulating valve automatically changes with the driving condition, and the steplessly adjustable function and the wide adjusting range are realized, so that a vehicle has excellent smoothness andmaneuverability; and meanwhile the damping regulating valve has the beneficial effects of being simple in structure, sensitive in response, high in reliability, free of sensors and power sources, lowin cost and the like.