In the "Hydrology - Hydrology year method - Sequence" tool under the reference plan condition, I could not set the hydrology year of the reference plan, it seemed to have a bug, I opened the "sequence" and it was blank. I really hope to get your help and answer.

Dear Wenying,
When you say you could not set the "hydrology year of the reference plan", do you mean you could not choose between Very Dry, Dry, Normal, Wet, Very Wet?
You should be able to choose this for the Current Accounts year when you select "Current Accounts" in the "Data for:" window.
All other years (ie the Current Accounts year +1 through the last year of your scenarios) can be set when you select a scenario in the "Data for:" window.
If this does not answer your question, please reply with more details.

Anne