Some key problems about the information fault tolerance and channel fault tolerance in the post-emergency control are discussed. Because the post-emergency control is the information control based on multi-agent information exchange system， the paper constitutes the extensive information model of multi-agent power system based on conventional information theory. Via“information transfer group and transmit”， the characteristics of autonomy， intelligence， inter-activeness of multi-agents system are synthesized with information theory in post-emergency control to implement the fault tolerance function. The information fault tolerance is realized via information differentiation and decision based on decision-making principle of information loss minimization and the channel fault tolerance implemented via the customization and resolution of inter-content in multi-agent. Finally with the application and simulation of an example， the validity and feasibility of fault tolerant function of multi-agent information system in post-emergency control is testified.