A random lattice fluid model with finite coordination number is a versatile molecular-based lattice fluid equation of state, but this model fails to reproduce the non-analytical, singular behavior of fluids in the critical region. In this work, a method of obtaining the classical critical properties is presented in the random lattice fluid model. This model is combined with the crossover theory to obtain the crossover random lattice fluid model and to calculate the thermodynamic properties of hydrocarbons and carbon dioxide. This crossover random lattice fluid model presents much better agreement with experimental data near to and far from the critical region than the classical random lattice fluid model.