Provided are a multi-screen control method and device. The method comprises: a server receiving a first access request message sent by a terminal, and receiving a second access request message sent by a set top box; the server determining a network platform to which the terminal belongs according to the first access request message, and determining a network platform to which the set top box belongs according to the second access request message; and the server sending an internet protocol (IP) address corresponding to the network platform to which the terminal belongs to the terminal according to the network platform to which the terminal belongs, and sending an IP address corresponding to the network platform to which the set top box belongs to a proxy server corresponding to the set top box according to the network platform to which the set top box belongs. By means of the present invention, the problem in the related art that multi-screen message interaction cannot be performed normally is solved, thereby guaranteeing network intercommunications between a terminal, a set top box and a server, and implementing normal multi-screen interaction.