[en] We study supersymmetry breaking from a lattice model of $\mathcal{N}=2$ supersymmetric quantum mechanics using a direct computational method proposed in arXiv:1803.07960. The vanishing Witten index is realized as a numerical result in high precision. The expectation value of Hamiltonian is evaluated for the double-well potential. Compared to the previous Monte Carlo results, the obtained vacuum energy coincides with the known values within small errors for strong couplings. The instanton effect is also reproduced for weak couplings. The used computational method helps us to evaluate the effect of finite lattice spacings more precisely and to study a non-perturbative mechanism of supersymmetry breaking from lattice computations.