How can I choose the true door/way in the polar ice field and krypts? Please show me. I've played it lots of time but still can't win it

It's random, there is no set correct path, you just need to be lucky.

There isn't one fixed way to get through. It's totally random for both of them.

well...so it may take more lots of time because I'm not a lucky person :(

That's part of the fun. If it were easy there would be no point in doing it :] A lot of people stick to the same path each time as it'll work eventually, you might have better results that way.?