The invention belongs to the wireless network communication technology and applies to a network communication technology in an indoor high-density wireless environment. According to a communication method for a network communication application layer of an ancient book protection box system, multi-functional instruments are in wireless communication with a relay device, the relay device is in wired communication with a central control center, and the protocol stipulates structures and formats of data and command information, stipulates an inquiry response relation between commands and data information and stipulates a transmission sequence of the commands and the data information. Real-time performance of communication is improved while communication reliability of a wireless network is guaranteed through combination of a UDP (user datagram protocol) and an application layer retransmission mechanism; under the action of unified control for communication initiation and termination modes, real-time delivery of communication information is guaranteed, and the utilization rate of channel resources is increased; due to detailed regulations of transmission data formats, coding and decoding efficiency is improved; by means of multi-digit coding confirmation for key information, acquisition reliability of key parameters of an ancient book packaging box is improved.