A criminal record can hinder your plans to work in Canada, however, you may have options to overcome inadmissibility.
If you have a criminal record and do not address inadmissibility before you apply for a Canadian work permit, you risk being refused entry to Canada.
You may be able to overcome criminal in admissibility depending on the crime, how long ago it happened, and how you have behaved since. In order to come to Canada with a criminal record, you will need to meet the legal terms to be deemed rehabilitated, or have a temporary resident permit or a legal opinion letter.
Whichever option ends up being the best for you, it is important to start the process well in advance of your intended travel to Canada. Here is some general information on ways to overcome inadmissibility to Canada.