A number of things can cause this, check the console output when you launch it, perhaps it has something relevant.
Thanks for your helping, I have already correctly installed dolphin. The problem I encountered is the dbus does not automatically run on MacOS, however, I really want to have a dolphin on my Mac is because the focus terminal panel is really useful for me. But I found that the Mac version KDE do not support this, am I right? I have asked GPT and it tells me I have to install KonsolePart, but KonsolePart is hard to install on Mac.
Kate managed to have the KonsolePart work on Mac, but I don’t think the same changes have been done to Dolphin.