  Space-based gravitational-wave (GW) detectors, including LISA, Taiji and
TianQin, are able to detect mHz GW signals produced by mergers of supermassive
black hole binaries, which opens a new window for GW astronomy. In this
article, we numerically estimate the potential capabilities of the future
networks of multiple space-based detectors using Bayesian analysis. We modify
the public package Bilby and employ the sampler PyMultiNest to analyze the
simulated data of the space-based detector networks, and investigate their
abilities for source localization and testing the parity symmetry of gravity.
In comparison with the case of an individual detector, we find detector
networks can significantly improve the source localization. While for
constraining the parity symmetry of gravity, we find that detector networks and
an individual detector follow the similar constraints on the parity-violating
energy scale $M_{\rm PV}$. Similar analysis can be applied to other potential
observations of various space-based GW detectors.
