It is well known that traditional routing protocols such as OSPF have mature and efficient mechanism to deal with the convergence problem. But, it is different in hierarchical routing ASON network. The optical network has its own distinct routing features, topology aggregation and abstraction used in inter-domain routing make the view of network topology different to each routing layer, all these factors demand a creative way to converge and synchronize the hierarchical network. This paper will depict the architecture of ASON hierarchical routing and the requirement of inter-domain routing. Based on the fundamental depiction, the factors that affect the convergence and synchronization of ASON network will be focused on and critical issues of the reasonable layout of routing layers, topology synchronization between layers, the triggering of topology update etc will be worked over. In this paper, we try to bring forward a kind of parallel topology convergence mechanism depending on the exchange of topology abstracts information, which is suitable for inter-domain routing in multiple layers and domains ASON network. The corresponding performance analysis will also be presented. Also we analyze the update triggering with relative threshold which will be useful to reduce the diffuse range and amount of the update messages in hierarchical routing. These new methods will decrease the convergence time efficiently and improve the efficiency of topology refresh.