Abstract: The present disclosure relates to a method and system for constructing a fusion covert channel. A time covert channel is constructed by rearranging data packets of different terminals in the Internet of Things in a manner of carrying secret information, a storage covert channel is constructed by replacing a TCP sequence number field of a data packet with secret information, and a fusion covert channel is constructed by fusing the time covert channel and the storage covert channel. In this way, advantages of the two channels can be complemented, so that covertness of the fusion covert channel is improved and a capacity of the covert channel is increased.