A protection structure for waterproof protection of an electrical device, including first and second shells connected to each other forming an outer shell, the first and second shells respectively including first and second reinforcement walls on their inside, and a sealing member disposed between the first and second reinforcement walls to form a waterproof seal between them. The protection structure employs a dual-layer structure, where the outer shell is a first protection layer that protects against high impact, high pressure water flow, and the sealing member with the first and second reinforcement walls form a second protection layer which is tightly waterproof to protect against water droplets, vapor and dust. The first protection layer protects the second protection layer from external impact and prevent it from being deformed, enhancing the overall protection effectiveness. The protection structure is easy to manufacture, low cost and easy to repair, and provide high waterproofness.