Efficient organization and querying of trajectory data is one of the research hotspots in spatial database field. By taking advantage of the properties of globally unique, one-dimension and hierarchically recursive coding of Geohash codes, oriented to relational spatial database, we proposes a Geohash-baesd organization method of large trajectory data and its range query processing technology. First, a trajectory relational schema, which combines Geohash coding and B+ tree index, is designed for range queries at multiple scales. Then, a corresponding two-stage range query processing algorithm is introduced. Next, we come up with Z-merge optimization for further improving the efficiency of range query processing. Finally, the experiment results based on Oracle11g verify that our approach is fit for organizing large trajectory data and its range query performance is much better than traditional R-tree.