Hello Yuefeng,
From my understanding, OneCollect tool is more for support data collection and less of an inventory tool.
NetApp OneCollect is a data collection tool that collects data from ONTAP, E-Series, Solid Fire, various operating system hosts and switches. OneCollect tool can be used by Customers, Partners and Internal users. The collected data is used for troubleshooting, solution validation, migration and upgrade assessments. This data will be stored in ASUP and presented for use by various other tools like SmartSolve, ConfigAdvisor and Unified Parser.
https://community.netapp.com/t5/Data-Infrastructure-Management-Software-Articles-and-Resources/NetApp-OneCollect-The-tool-for-easy-consolidated-diagno...
Please give a feedback if this answers your question or not so we can further assist you on this.
Thanks.