People are dependent on Social Media Networks (SMNs) to get in time information about crises. Therefore, emergency managers are interested in how individuals participate in social media networking sites after crises, as well as in how to encourage their participation. Based on the theory of self-determination, this study builds a theoretical model to investigate how various varieties of motivation lead to different kinds of participation in SMNs after a crisis. A survey was conducted after COVID-19, which occurred in China and Europe at the end of December 2019. The 310 data were gathered by a "time-lagged, two-wave survey" and "convenience sampling." According to the findings of this study, autonomous motivation is strongly linked to posting new COVID-19 content, while controlled motivation is significantly linked to commenting on others' COVID-19 content. Moreover, perceived autonomy and perceived relatedness are positively associated with autonomous motivation. This study proposes that crisis managers might wish to enhance various kinds of motivations; dependent on the particular take-part behavior chosen post crises. Moreover, perceived autonomy and relatedness are positively associated with autonomous motivation. The study proposes that risk managers may seek to promote different forms of motives based on the preferred style of participation after a crisis.