The present invention relates to a method of building a dynamic overlay network topology based on cross-chain interaction between blockchains, at least comprising: selecting at least one gateway node and at least one ordinary node from at least one cross-chain interaction node; clustering the ordinary nodes into ordinary node clusters based on a clustering algorithm; building a structured network topology and cross-chain connections between the cross-chain interaction nodes based on the gateway node; performing topology building on the ordinary node clusters based on a breadth-first spanning tree algorithm.