Cross-network data exchange system capable of preventing information from being lost and repeated

The invention relates to the field of data exchange systems, in particular to a cross-network data exchange system capable of preventing loss and repetition of information, which comprises a distributed information processing server used for acquiring the character length and segment signal generation times of data to be transmitted; the external front data switch is used for acquiring an information chain segment according to the segmented signal and the information to be transmitted; the key network switch is used for generating key information according to the information chain segment and obtaining cache information according to the information to be transmitted and the corresponding key information; the internal front data switch is used for acquiring the data loss signal and acquiring a data set to be transmitted according to the data loss signal, the key information and the cache information; and the data receiving server obtains the non-duplicate information chain segment and obtains the receiving inf