We calculate potentials between a proton and a \(\Xi^0\) (hyperon with strangeness -2) through the equal-time Bethe-Salpeter wave function, employing quenched lattice QCD simulations with the plaquette gauge action and the Wilson quark action on (4.5 fm)^4 lattice at the lattice spacing \(a \simeq 0.14\) fm. The ud quark mass in our study corresponds to \(m_{\pi}\simeq 0.37\) and 0.51 GeV, while the s quark mass corresponds to the physical value of \(m_K\). The central \(p \Xi^0\) potential has a strong (weak) repulsive core in the \(^1S_0\) (\(^3S_1\)) channel for \(r \lsim 0.6\) fm, while the potential has attractive well at the medium and long distances (0.6 fm \(\lsim r \lsim 1.2\) fm) in both channels. The sign of the \(p \Xi^0\) scattering length and its quark mass dependence indicate a net attraction in both channels at low energies.