When processing inquiry/update task of large-scale XML file currently, massive internal memory space and time are required, processing efficiency of XML file is influenced, and load of system is greatly improved. The invention discloses a method for buffering node elements when rapidly processing large-scale XML file, including that: an XML file is read into an internal memory, an XML node is analyzed when reading, position and type of node are taken as additional information to be stored into the internal memory, the XML node modified by user is buffered by virtue of a buffer zone, and meanwhile completeness of index information is maintained. The invention buffers content modified by user and processes the content modified by user only, and the processing method reduces usage of internal memory and reduces inquiry response time.