Triple-based hierarchical interconnection network (THIN) is not only a new kind of direct networks but also a kind of HIN?s. Efficient routing algorithm is very essential to the performance of the interconnection network and the parallel computing system. This paper presents DDRA (Distributed Deterministic Routing Algorithm) routing algorithm in triple-based hierarchical interconnection network. Fully applying the hierarchical characteristic of the network, DDRA routing algorithm just uses the node address to determine an approximate minimal path between source and destination node, without constructing the route table on each node. The analysis based on the simulation of DDRA shows it is not only very simple and easy to be implemented in hardware, but has high efficiency.