A clear conscience laughs at false accusation, which means "只要問心無愧, 無端指責可一笑置之."
It is one of the English Proverbs which taught us not to care about the accusation that people blame on you. Because you know it is not true, so you don't need to care the words they say trying to hurt your feelings. If you have a clear idea about what you are doing, you will have full confidence and be strong enough to face the challenge in the future. As the old saying goes, after a storm comes a calm & after rain comes sunshine. Just keep on going, you will taste the sweets of success in the near future.