The invention discloses a double-layer self-locking pin. The double-layer self-locking pin comprises an umbrella cap, the middle of the umbrella cap is connected with a pin rod, an upper gasket is arranged below the umbrella cap, the pin rod penetrates through the middle of the upper gasket and is fixedly connected with the upper gasket, and a lower gasket is arranged below the upper gasket. According to the double-layer self-locking pin, holes do not need to be punched, materials can be punched directly through cooperation of pins and a matched nailing machine, direct one-time forming is achieved, and long time can be saved; the thickness of a product can be adjusted without customizing pins with various lengths; the circular-arc-shaped umbrella cap is of a double-layer design and is attractive, elegant, firm and durable; and when a customer installs the umbrella, due to the fact that the 360-degree circular opening is formed between the umbrella cap and the lower gasket, the customercan sleeve the connected stainless steel wire or spring without seeing the umbrella with eyes, installation and operation are easy, and the umbrella is very convenient to use and practical especiallyin narrow space.