Moving objects database （MOD） manage spatial objects that continuously change their locations over time and have been studied in a wide range of applications. Although a number of relevante techniques have been proposed such as indexing and query algorithms， cache management in MOD has been ignored. This is essentially important for database performance. Traditional cache methods ignore the spatial-temporal characteristics of data and cannot achieve good performance. This paper proposes to fully exploit the query performance of trajectory data from the cache level. Firstly， based on the unique storage structure and read/write process of trajectory data， a cache access mechanism suitable for MOD is designed. Then， due to the lack of cache policies related to application scenarios and access modes in MOD， a cache replacement strategy is customized. Finally， a cache management tool MOCache for trajectory data is implemented. By utilizing MOCache， dynamic tracking of cache state changes is visualized after each query statement. Compared with traditional algorithms， the proposed cache replacement strategy improves the hit ratio to 76.56% and reduces query time， and using the cache tool to monitor historical state information can facilitate comprehensive feedback and analyze performance problems.