I prefer ibeam cursors to the block ones, I find them less obtrusive. However, I could not find an option to modify the cursor shape in the XFCE terminal preferences; until I looked under the hood. In ~/.config/Terminal/terminalrc the value of MiscCursorShape is set toTERMINAL_CURSOR_SHAPE_BLOCK(方块) by default. Change it to TERMINAL_CURSOR_SHAPE_IBEAM(I 型) for an ibeam cursor or to TERMINAL_CURSOR_SHAPE_UNDERLINE(下划线) if you want an underline.

I wish all application developers kept an underlying readable text file for configuration. In addition to being light-weight and portable, they are transparent and offer an efficient way of configuration, without having to even start the application.