  Using the latest AMS-02 cosmic ray antiproton flux data, we search for
potential dark matter annihilation signal. The background parameters about the
propagation, source injection, and solar modulation are not assumed {\it a
priori}, but based on the results inferred from the recent B/C ratio and proton
data measurements instead. The possible dark matter signal is incorporated into
the model self-consistently under a Bayesian framework. Compared with the
astrophysical background only hypothesis, we find that a dark matter signal is
favored. The rest mass of the dark matter particles is $\sim 20-80$ GeV and the
velocity-averaged hadronic annihilation cross section is about $(0.2-5)\times
10^{-26}$ cm$^{3}$s$^{-1}$, in agreement with that needed to account for the
Galactic center GeV excess and/or the weak GeV emission from dwarf spheroidal
galaxies Reticulum 2 and Tucana III. Tight constraints on the dark matter
annihilation models are also set in a wide mass region.
