Abstract: A wireless network system for data transmitting securely is disclosed. The system comprises a central control end for generating a cipher password per predetermined time unit. The central control end has a first Zigbee chip, a computer terminal for a user to input parameters, and a cryptographic algorithm program provided wherein the cryptographic algorithm program and the parameters are provided for password encryption using the cryptographic algorithm program is run by a microprocessor of the first Zigbee chip. The system also comprises a data transmitting end and a several data receiving ends. The data transmitting end using the Zigbee decrypts the cipher password and encrypts the data file using the plain password and the Zigbee chip. The data receiving ends using the Zigbee decrypt the cipher password and decrypt the cipher data file into plain data file by the WiFi chips using plain password.