Reliable acoustic path（ RAP） is one of the special physical phenomenon in deep ocean sound propagation. Physical mechanism of RAP is analyzed and RAP is used to calculate distribution of acoustic field. On the basis of deep ocean underwater acoustic network communication nodes

combined with graph theory

simulate connectivity of deep ocean underwater acoustic network in the condition of complex seabed topography. The results show that this method can effectively estimate if deep ocean underwater acoustic network is connected

and can find a optimal path from source to receiver when the network is connected.