According to the Law of People's Republic of China (PRC) on Exit and Entry Administration, China citizens are not allowed to leave the country under any of the following circumstances:
1. Defendants in criminal cases and persons who are not allowed to leave the country as notified by public security organs, people's procuratorates and people's courts;
2. If it is impossible to leave the country because the civil case is not settled, the people's court shall notify it;
3. People who are serving sentences;
4. The people's court is trying a civil case or a criminal case, and the final judgment has not been made because the contents involved are being tried or reviewed.
Therefore, if you have a criminal record, you can't apply for a Hong Kong work endorsement.