The critical properties of square-well dimer with range λ＝1.5 are calculated by grand ensemble Monte Carlo simulation. The critical temperature and density obtained with the help of histogram reweighting technique and finite-size scaling theory are and , respectively. Vapor-liquid equilibria properties far from the critical point are explored by hyper-parallel tempering method which can greatly improve simulation efficiency. The result of critical properties is much more precise than previous simulation result.

Key words: Monte Carlo method, square-well dimer, critical property, vapor-liquid equilibria