  The gravitational wave (GW) has opened a new window to the universe beyond
the electromagnetic spectrum. Since 2015, dozens of GW events have been caught
by the ground-based GW detectors through laser interferometry. However, all the
ground-based detectors are L-shaped Michelson interferometers, with very
limited directional response to GW. Here we propose a three-dimensional (3-D)
laser interferometer detector in the shape of a regular triangular pyramid,
which has more spherically symmetric antenna pattern. Moreover, the new
configuration corresponds to much stronger constraints on parameters of GW
sources, and is capable of constructing null-streams to get rid of the
signal-like noise events. A 3-D detector of kilometer scale of such kind would
shed new light on the joint search of GW and electromagnetic emission.
