Children need to realize the reality and cruelty of society when they grow up, but the way and time of education need to be moderate and cannot be overemphasized. Here are some suggestions:

1. According to children's age and psychological development level, introduce some practical social problems appropriately. For example, when introducing social injustice, we can use examples and situations close to children's life experiences to make them understand.

2. Avoid using language and scenes that are too horrible and violent, so as not to cause too much harm and negative impact on children's psychology.

3. Emphasize positive attitudes and values, and let children know that in this complex society, only firm beliefs and correct actions can lead to success.

4. Let children learn to face difficulties and setbacks, and encourage them to actively explore and try in their study, life and social life.

In short, parents should educate their children to understand the cruelty of society in a gentle way, let them understand the injustice and imperfection of society, and at the same time cultivate their positive and optimistic attitude and correct values, so that they can move towards a better future.