  Wormholes bridging distant places of the universe are well-known solutions of
general relativity. In particular, traversable wormholes which allow
interstellar traveling are also popular in science fiction. However, no hint of
their existence has been found yet. In this work, we propose using the
gravitational wave (GW) scattering off spherical wormholes to search for their
existence. We carefully calculate the reflected and transmitted waveforms with
time-independent scattering theory. Our results quantitatively show the echo
signatures in the two universes on both sides of the wormhole. In a certain
wormhole mass range, the transmitted wave has a unique isolated chirp without
an inspiral waveform, and the reflected wave has the anti-chirp behavior, i.e.,
the missing of the chirping signal. We also calculate the searching range of
the current and projected GW telescopes. Our method can be adapted to
efficiently calculate the templates to search for wormholes.
