Abstract: The present invention provides an optimized quantum Monte Carlo method. The method comprises the following steps. S1: the spin or magnetic moment in a system Hamiltonian is a quantum mechanical operator, and all physical quantities being calculated according to the quantum theory. S2: initiate all spins' orientations randomly at the beginning. S3: randomly select one spin in each step, and rotating it by a random three-dimensional angle. S4: judge whether the new orientation of the spin is acceptable according to the Metropolis algorithm. S5: if it is acceptable, update the energy states of neighbors. S6: judge whether the current cycle is finished, if not, returning to S3. S7: judge whether the current circle meets a convergence condition or the number of circles is greater than a certain integer, if not returning to S3. S8: calculate and output the magnetic structure and other physical quantities.