Inglehart’s theory of postmaterialism outlines the influence of intergenerational value change on social change. While the sense of security during a formative period is an essential context for postmaterialist values to be bred among the younger generation in democratic states, social protests and political instability are common in some hybrid regimes. Yet how social protests in a hybrid regime interfere in the building of postmaterialism and its association with other value has been underresearched. Based on the data collected from the seventh wave of the World Value Survey in Hong Kong in 2018 (N = 1,031), this paper investigates the role of a critical event—the Umbrella Movement in 2014—in moderating the relationship between a postmaterialist orientation and perceived quality of elections in Hong Kong. It reveals that the negative relationship between a postmaterialist orientation and perceived quality of Hong Kong’s election was stronger among the people who supported and participated in the Umbrella Movement. Moreover, the moderation effect of the Umbrella Movement was stronger among young people. This paper underscores the context of socialisation in influencing both a postmaterialist orientation and intergenerational change occurring during a critical event, which sheds light on the relationship between value change and authoritarian resilience.