Nowadays, all kinds of climate disasters, such as global warming and the melting of glaciers, are happening all over the world. Human beings also gradually realized the importance of protecting our only earth and took some measures. Green cities were proposed in the course of the "Green Movement" to protect the global environment. The green city refers to urban construction that emphasizes not only ecological balance and nature protection but also human health and cultural development. Curitiba, Brazil, as one of the representatives of green cities, has not only made innovations in the city's public transport system, BRT but also combined the urban park green space with water control, which not only managed the flood disaster but also provided leisure and entertainment space for citizens. At the same time, they also advocate the EcoCitizen program, which encourages citizens to exchange garbage for food and solves the problem of garbage sorting and recycling and also deals with most of the excess food. At the end of the article, we also searched some pieces of literature and video interviews with Curitiba residents to discuss whether these measures are effective as advertised by the government, as well as the existing problems of green space fairness and the bicycle system. And take Curitiba as a case to summarize and analyze.