Hierarchical optical cross-connects has the potential to enhance the performance/cost ratio of optical networks by providing transparent switching of sets of wavelengths.By focusing on network topology and traffic pattern of the optical network,a normal mathematics model which describes the requirements of equipment ports and cost-saved in the network is presented.The result demonstrates a significant cost reduction achieved by employing hierarchical cross-connects in optical ring network(e.g.,for about 65% saved in 19 nodes ring network).Further analyzing,the model has more general purpose.It can be used in most common network such as:ring with line,multi-rings and mesh network,and arbitrarily traffic pattern.