Quantum chromodynamics(QCD)is established as the fundamental theory of strong interactions.At low energy regime,the coupling of strong interactions is large,non-perturbative methods are required to study the properties of strongly interacting matter.Lattice QCD is the only method that can study strong interactions from first principles and provide reliable numerical results with controllable uncertainties.The basic idea is to define QCD on a discretized Euclidean space and solve it numerically on supercomputers using Monte Carlo simulations,as illustrated in Fig.1(a).