The invention discloses a device interconnection method and a device interconnection system based on a Smart PnP protocol. The method comprises the following steps: a center smart household appliance sends an available service query instruction to a predetermined distance range around; a peripheral smart household appliance within the predetermined distance range receives the query instruction, generates reply information according to a preset format, and sends the reply information to the center smart household appliance; and the center smart household appliance and the peripheral smart household appliance are interconnected after the center smart household appliance receives the reply information. Communication between smart household appliances in the Internet of things adopts a Smart PnP protocol based on an REST structure. Therefore, the communication protocol of smart household appliances can be conveniently combined with an HTML5 technology, the compatibility of devices is improved, the hardware requirement of smart TV client networking is lowered, the software design is simplified, and convenience is provided for users.