Nuclear Power Institute of China (NPIC) developed an advanced neutron transport lattice code, namel KYLIN-2. To solve the problem of mass data storage and processing in software, a computing data storage solution based on Hierarchical Data Format v5 (HDF5) was proposed. Firstly, HDF5 file format was researched. Secondly, according to the requirements of KYLIN-2, KYlin-2 Main RESults databank (KYMRES) based on HDF5 was designed. Finally, KYMRES was realized by self-developed HDF5 read/write tool. The performance tests show that KYMRES has a higher I/O efficiency compared with conventional storage solutions, the efficiency of reading and writing is increased to 2.3 and 4.5 times on average that of the old algorithm. KYMRES has significant advantages in mass data storage and processing. and provides a new data storage and management solution for KYLIN-2.