Since the Justin Trudeau's administration，Canada proclaimed “we are back on the world stage”and engaged in international affairs through active multilateral diplomacy.From extensive engagement，intensive activity to adaptive adjustment，Trudeau's multilateral diplomacy in the main form of summit diplomacy，not only promotes Canadian values but also sets the “green”priority in Canadian foreign agenda.However，the Trudeau's administration may face more challenges and opportunities in the future.The new U.S.administration restricts the space of Canada's multilateral activities.Canada will consolidate the multilateral relationship with the Atlantic allies.Asia-Pacific will become the key point in the expansion of Canada's multilateral diplomacy.Furthermore，Canada will devote to bringing homegrown solutions to the global challenges in the field of climate change and refugee issues.