In 1757, colonial leader Klewu led British troops to occupy Bengal India and began to colonize India. Since then, India was under British’s governance for many years. The upsurge of global national independence and national liberation movement after World War II led India to explore breaking away from the control of the supranational state, and finally realizing the political goal of building a nation-state. However, after the victory of World War II, Britain failed to fulfill its promise to give the independence that the Indian people wanted, which aroused the anger of the whole India, and the growing resistance influenced by the world national liberation movement kept rising. In February 1946, a large-scale insurgence broke out in India, requiring India to get rid of its colonial status, to escape from British’s control, and to achieve true independence. In view of the tension in India, the British government announced in February 1947 that it would return its state power to India in June 1948. Later, the two dominions of India and Pakistan began to exercise self-government independently, which eventually led to the establishment of their own countries. The nation-state construction of India and Pakistan is a final product influenced by not only internal factors including England and India, but also various external factors. To study the external influencing factors of the two countries in the process of nation-state construction can not only find out the influencing factors of historical events, but also provide reference for the research on the development of politics, economy and culture of the two countries. Meanwhile, the influence of external factors on the national construction of India and Pakistan also has certain reference significance for the historical and cultural research of the founding process of South Korea and North Korea in Northeast Asia. This paper adopts the method of literature research to analyze the external factors in the process of state construction of India and Pakistan respectively, and then integrate the influence of external factors on the construction of nation-states of the two countries. It finds that the Muslim ethnic homogeneity, the Soviet Union and the United States are the external factors that affected the nation-state construction of India, while the collapse of the Ottoman Empire and the United States are the external factors that affected the nation-state construction of Pakistan.