Owning to similar business nature, it should be possible to directly migrate successful independent hotel revenue management techniques to the economy hotel in one city. However, one of the salient differences between independent hotel and economy hotel is that one economy hotel usually has many chains in one city. So, not only the chain hotels' revenue but also the global revenue should be considered. Based on the principle of revenue management, in this paper we build a system framework which includes demand forecasting, optimal room allocation and real assignment modules. According to the system, the manager can allocate the customers to the optimal room online which can make the hotel revenue better. The demand forecasting module and real assignment module are basically same as the revenue system of independent hotel. Here, we mainly design the optimal room allocation module. In the optimal room allocation module, a stochastic model was established to allocate the rooms and achieve the global optimization. The robust optimization was used to the stochastic variables so as to turn the stochastic into a linear programming problem, and then solve the model. Finally, we will illustrate examples to explain the models' validity.