Hello! Whole the day I can’t withdrawal my XCP coins from XCP on Poloniex to my XCP wallet on Bittrex. Status is PENDING, why does it take so much time? Plz help me with this situation.
Poloniex has a long history of randomly disabling XCP withdrawls without explanation, and then trying to blame Counterparty for their issues.
I would suggest you
1.) Re-tweet this tweet to bring more attention to this issue (and add a comment to show your also having issues)
2.) Stop using Poloniex and switch to an exchange like bittrex.com as they do not have any of the same issues that polo has with XCP Withdrawals.
can I cancel this transaction without problems?
Unfortunately there is nothing you can do but sit on your hands and wait for Poloniex to reply to you. 
Ahh… I have not seen that cancel button before. You might be able to cancel your pending withdrawal and have the funds returned to your account.
Thank you 