  The Jiangmen Underground Neutrino Observatory(JUNO) experiment will develop
an internationally leading neutrino experimental station to measure the order
of neutrino mass and carry out many other scientific frontier studies. The
entire experimental system includes the detector system, the electronics
system, and the data acquisition (DAQ) system. Data flow is the core of JUNO
DAQ system. Readout system and Event Building (EB) system are two key aspects
of data flow. Based on the requirements analysis of JUNO DAQ, this paper
proposes a data flow schema of distributed network readout and second-level
event building. Focusing on the performance requirements of JUNO DAQ, the
performance of the readout and event building module, the number of readout
processes deployed on each node, and integration performance of the two modules
are studied. The results of the research provide a reference for further
optimization of the JUNO DAQ data flow framework
