The continuous development of human society has led to increasing needs for resources，which has triggered the growth in non-traditional security problems，threats and crises across borders. National security strategy of every country must be based on theoretical analysis of non-traditional security threats and assessment of the real impact of non-traditional security threats. Non-traditional security is essentially a category of “field security”，characterized by complexity and asymmetry. External non-traditional security threats arise from global，regional or foreign causes. They need to be addressed through multinational corporations and co-governance in accordance with the principle of achieving shared growth through discussion and collaboration. External non-traditional security threats can be divided into two categories：one is global threats and the other is predominantly international or regional threats which can evolve into global or national threats. These threats have a significant impact on national security. Although external threats only account for 30% of the non-traditional security challenges facing China，they are more complex and challenging than internal threats. They often overlap with military affairs in terms of purpose，means and process. Therefore，to solve complex non-traditional security issues，China needs to strengthen capacity building in the field of cross-border governance.