Happiness is an important compositive part of the comprehensive national power, national quality of life and psychosocial system. The subjective well-being SWB is an important comprehensive psychological indicator to measure the quality of personal life, which is of great significance to the study of well-being The GDP per capita of the five Nordic countries are among the Top 20 in the world, and, and their average life expectancy is also very long. Particularly, their social welfare systems are leading the world. The "high degree of happiness" in the Nordic countries is manifested in all aspects of social life and is the result of a combination from all different kinds of causes. The "Nordic model" has much significance for human societies development as a big reference. However, we must also see the shortcomings behind this model and the social problems in various Nordic countries today. The purpose of this article is to interpret the specific manifestations and causes of happiness in Nordic societies, and to evaluate and summarize the reference and remaining deficiencies of the "Nordic model" objectively.