Daga baya, Cheung ya shiga Jami'ar Hong Kong da ke ƙasar Caina, don ya yi karatun siyasa da kuma gudanar da harkokin gwamnati. Ya zama shugaban kungiyar dalibai a shekarar 2014 kuma memba na Hong Kong Federation of Students (HKFS). Ya shiga cikin manyan zanga-zangar Occupy
a shekarar 2014 a kan shawarar da Beijing ta yanke game da tsarin zaben Shugaban zartarwa na 2017. Ya zama daya daga cikin manyan mutane tara da aka kama a shekarar 2017 saboda fara taron haram.