An electrical toothbrush head includes a toothbrush body and an insertion piece that includes a core channel and a sideway slot in which an elastic bar is arranged. The core channel has a contact engagement surface. The elastic bar has a curved section. When the vibration core is inserted into the core channel, the contact engagement surface and the curved section respectively contact and engage with core side surfaces of the vibration core, and the elastic bar is pushed to elastically deform away from the contact engagement surface. When the electrical toothbrush head and the toothbrush handle are combined, the vibration core is clamped between the contact engagement surface and the curved section and the elastic bar deforms outward and the elastic filler block is compressed, such that the elastic filler block and the elastic bar cause the curved section to be in elastic engagement with the vibration core.