The invention provides a self-closing type foam spray nozzle. The spray nozzle is used for a foam fire extinguishing system and comprises a connecting head, a flow dividing cylinder and a normally-closing cover assembly; the connecting head is provided with a first end and a second end, the first end is connected with a flow collecting pipe of the foam fire extinguishing system, a spray opening is formed in one end of the flow dividing cylinder, a connecting opening is formed in the other end of the flow dividing cylinder, the connecting opening of the flow dividing cylinder is connected with the second end of the connecting head, a flow dividing disc is arranged in the connecting opening of the flow dividing cylinder, and a plurality of spray holes are formed in the flow dividing disc; the normally-closing cover assembly is assembled on the flow dividing disc in a sliding manner, a spring is arranged between the normally-closing cover assembly and the flow dividing disc, and the normally-closing cover assembly blocks the spraying opening of the flow dividing cylinder under drive of the spring. When the self-closing type foam spray nozzle is not used, the spray opening can be automatically closed so as to prevent foreign matter from entering the spraying opening, the spray holes in the spray opening can be protected against blockage, and the flow and the spray radius cannot be affected.