  In this paper, we study a Landis-type conjecture for the general fractional
Schr\"{o}dinger equation $((-P)^{s}+q)u=0$. As a byproduct, we also proved the
additivity and boundedness of the linear operator $(-P)^{s}$ for non-smooth
coefficents. For differentiable potentials $q$, if a solution decays at a rate
$\exp(-|x|^{1+})$, then the solution vanishes identically. For
non-differentiable potentials $q$, if a solution decays at a rate
$\exp(-|x|^{\frac{4s}{4s-1}+})$, then the solution must again be trivial. The
proof relies on delicate Carleman estimates. This study is an extension of the
work by R\"{u}land-Wang (2019).
