A scheme for wide-area Quantum Secure Direct Communication (QSDC) Network based on decoy states is proposed.A server which is used to prepare and measure photons,is set in each local area network,so the communication distance increases.In addition,the idea of decoy states,which is to send photon pulses of different intensities to detect Photon Number Splitting (PNS) attack,is introduced to QSDC to improve the security of the communication.And,the transmission probability is estimated based on the channel parameter,which can be used as a reference for channel coding.Security analysis result shows that this protocol can be used to realize long distance QSDC.