A striking device includes a swing arm unit, an impact member and two restoring units. Each of the restoring units includes a stationary seat removably connected to the swing arm unit, a moving seat removably and co-movably connected to the impact member, first and second coupling sets, and a resilient member interconnecting the stationary seat and the moving seat to bias the moving seat toward the stationary seat. For each of the restoring units, two portions of the first coupling set are formed respectively on the stationary seat and the swing arm unit and coupled removably with each other, and two portions of the second coupling set are formed respectively on the moving seat and the impact member and coupled removably with each other.