(1) Import substitution: The main method is to restrict the import of basic consumer goods by using high tariffs and quantitative measures, and at the same time encourage the import of raw materials and technical equipment needed by industry by using overvalued exchange rate, so as to support the development of emerging industries in China and realize the import substitution of basic consumer goods. Advantages of (1): ① laying a preliminary industrial foundation for a country; Give full play to the advantages of domestic resources; Ensure that foreign exchange is used in the most critical places. (2) Disadvantages: ① It hinders the development of exports and leads to the deterioration of the balance of payments; (2) ignoring the development of non-import substitution sectors; ③ Reject competition and reduce the overall economic efficiency. (2) Export-oriented: its main feature is gradually moving closer to the equilibrium exchange rate, and some still underestimate the exchange rate to encourage exports; Cancel the quantity limit. Advantages of (1): ① It is conducive to the acquisition of comparative benefits; (2) introducing competition mechanism; ③ Promoting export development; ④ Adapting to international trade norms. (2) Disadvantages: ① It is prone to imbalance of foreign exchange receipts and payments; ② Great dependence on foreign countries. The reason why developing countries choose protective trade policies in the early stage of industrialization is in the era of industrial economy, especially in the fifties and sixties. The economy of developing countries mainly depends on agriculture, and the national industrial base is weak, and a complete industrial system has not been formed. The economic structure is characterized by simplicity and deformity. The industrialization of developed countries has been fully developed, and the domestic market is increasingly saturated, so it is urgent to expand raw materials and sales markets overseas. Therefore, developed countries strongly advocate free trade. In principle, free trade requires international trade to be based on comparative advantages. Therefore, developed countries can sell their finished products to the vast number of backward countries in order to realize their economic expansion. However, backward countries can only produce and export primary products and labor-intensive products, the economic structure can not be improved and upgraded, and economic development will always stay at a backward level. Under the requirements of this asymmetric economic development, developed countries often vigorously promote imperialism and colonialism by virtue of their strength, exploit and plunder the economic resources of backward countries, and destroy and stifle their emerging industries. In this unfair international economic order, the economic independence and development interests of developing countries will not be fundamentally guaranteed. Facing the special historical background, development economists put forward the idea and slogan of protecting national industries in the 1960s. The proposal of protective trade policy has been recognized by developing countries and has become an inevitable choice in the early stage of industrialization. Through the protection of national industries, the establishment and development of national industries have gained certain space. The level of productive forces has been substantially improved. The protective trade policy transforms the inherent, static and low-level comparative advantage of backward countries into innovative, dynamic and high-level comparative advantage, which shows that the protective trade policy is reasonable under certain historical conditions.