I want to catch event and overide when delete a note by hot key Delete, help me please!
It depends on what you want to do. Please read GoJS Commands -- Northwoods Software if you want to sometimes prevent the Delete key from acting in the normal manner.
But if you want to perform additional work when a CommandHandler.deleteSelection happens, I suggest that you implement a “SelectionDeleted” DiagramEvent listener. DiagramEvent | GoJS API