Abstract: In the new era, doing youth work well, representing youth and winning youth is a major historical issue facing our party and an important part of party building work.In his later years,Engels pointed out that the German Social Democratic Party's "youth" treated Marxism in a dogmatic manner, trampled on the party's political life norms and made the violent view of the violent struggle absolute.Combining legal struggle with violent struggle.A deep understanding of Engels' criticism of the "Youth" of the German Social Democratic Party has important implications for the work of youth party building in the new era,that is, it is necessary to focus on theoretical guidance, cultivate young people to learn and use Marxism; strengthen the party organization's own construction and effectively Guide the work of youth well;use modern technology and methods to gather young people and increase the appeal of party organizations.