A method for recording data based on a plurality of blockchain networks, wherein a data recording system comprises at least two first-type blockchain networks and one second-type blockchain network; at least one node in each first-type blockchain network is managed by a designated manager, and at least one node in the second-type blockchain network is managed by the designated manager; the method comprises: when obtaining data to be stored, constructing, by a node in each first-type blockchain network, a first-type blockchain transaction comprising the obtained data to be stored, and broadcasting the constructed first-type blockchain transaction to the first-type blockchain network; when needing to write data to a blockchain, packaging, by each node in the first-type blockchain network based on a consensus algorithm, several first-type blockchain transactions into a first-type recording block and writing the first-type recording block into a blockchain of the node itself; obtaining, by a node managed by the designated manager in the second-type blockchain network, the first-type recording block and calculating a transaction hash of each first-type blockchain transaction in the first-type recording block; and constructing, for each transaction hash, a second-type blockchain transaction comprising the transaction hash and a network identifier of the first-type blockchain network, and broadcasting each second-type blockchain transaction to the second-type blockchain network; and when needing to write data to a blockchain, packaging, by each node in the second-type blockchain network based on the consensus algorithm, several second-type blockchain transactions into a second-type recording block and writing the second-type recording block into a blockchain of the node itself. wherein a data recording system comprises at least two first-type blockchain networks and one second-type blockchain network; at least one node in each first-type blockchain network is managed by a designated manager, and at least one node in the second-type blockchain network is managed by the designated manager; the method comprises: when obtaining data to be stored, constructing, by a node in each first-type blockchain network, a first-type blockchain transaction comprising the obtained data to be stored, and broadcasting the constructed first-type blockchain transaction to the first-type blockchain network; when needing to write data to a blockchain, packaging, by each node in the first-type blockchain network based on a consensus algorithm, several first-type blockchain transactions into a first-type recording block and writing the first-type recording block into a blockchain of the node itself; obtaining, by a node managed by the designated manager in the second-type blockchain network, the first-type recording block and calculating a transaction hash of each first-type blockchain transaction in the first-type recording block; and constructing, for each transaction hash, a second-type blockchain transaction comprising the transaction hash and a network identifier of the first-type blockchain network, and broadcasting each second-type blockchain transaction to the second-type blockchain network; and when needing to write data to a blockchain, packaging, by each node in the second-type blockchain network based on the consensus algorithm, several second-type blockchain transactions into a second-type recording block and writing the second-type recording block into a blockchain of the node itself. when obtaining data to be stored, constructing, by a node in each first-type blockchain network, a first-type blockchain transaction comprising the obtained data to be stored, and broadcasting the constructed first-type blockchain transaction to the first-type blockchain network; when needing to write data to a blockchain, packaging, by each node in the first-type blockchain network based on a consensus algorithm, several first-type blockchain transactions into a first-type recording block and writing the first-type recording block into a blockchain of the node itself; obtaining, by a node managed by the designated manager in the second-type blockchain network, the first-type recording block and calculating a transaction hash of each first-type blockchain transaction in the first-type recording block; and constructing, for each transaction hash, a second-type blockchain transaction comprising the transaction hash and a network identifier of the first-type blockchain network, and broadcasting each second-type blockchain transaction to the second-type blockchain network; and when needing to write data to a blockchain, packaging, by each node in the second-type blockchain network based on the consensus algorithm, several second-type blockchain transactions into a second-type recording block and writing the second-type recording block into a blockchain of the node itself.