好像沒什麼區別，請參考

look down one"s nose at someone or something;

look down on someone or something to view someone or something as lowly or unworthy.

She looked down at all the waiters and treated them badly.

They looked down on ourhumble food.

Don"t look down your nose at my car just because it"s rusty and noisy.

生活中，更多的用的是look down on

To look down on someone means to consider that person to be inferior or

unimportant, usually when this is not true.

I wasn"t successful, so they

looked down on me.