The invention relates to a client cross-region data distribution method based on a data leakage preventing system, and a system thereof. The system comprises a core server, a plurality of region mainservers, a plurality of load servers and a plurality of user terminals. The plurality of region main servers are distributed in different regions and are in a long connection with the core server. Theplurality of region servers and the region main server in the same region are kept in a long connection. The load servers in the same region can be interconnected. Each load server is connected witha plurality of user terminals. Through the core server, the data are distributed to the plurality of region main servers. Each region main server distributes the data to the plurality of load serverswhich are connected with the region main server in a flooding manner. The client cross-region data distribution method and the system thereof improve data distribution efficiency and furthermore support cross-region office affair handling by a user.