Wei Yuan resolutely opposed the invasion of China by western capitalism and put forward anti-aggression ideas and methods. He has a certain understanding of the power of the people, which is consistent with Lin Zexu's view that people's hearts can be used, and puts forward the idea that "just people can be used". He was inspired by the anti-British struggle of Sanyuanli and Taiwan Province people. After Sanyuanli people beat the British invaders, he enthusiastically eulogized Sanyuanli people's anti-British struggle, angrily denounced the shameful behavior of the capitulators to clear the way for the invading army, and wrote in Atlas of the Sea. He also said that "Guangdong killed barbarians, and those who donated ships were righteous people", and "Taiwan Province smuggled two birds, and those who attacked barbarians in South Australia were also righteous people". He advocated using and relying on the people as the main force to resist foreign aggression, which was in sharp contrast with the reactionary policy of the capitulators that "protecting the people is better than protecting the bandits".

In order to effectively resist, he opposed "wave war" and advocated "defending for war". He summed up the experience and lessons of the Opium War and put forward the second strategy of self-defense counterattack: first, it is better to defend Haikou than to defend Haikou, and it is better to defend inland rivers than to defend Haikou; On the one hand, it is better to train sailors than to train local soldiers, and it is better to train water brave than to train water engineers. It advocates adopting the strategy of luring the enemy in depth and "setting a tiger to fish" to annihilate the invaders. This kind of local people who think they are familiar with the situation, give full play to their strengths and enthusiasm for resisting the enemy to organize anti-aggression armed forces and adopt flexible strategies and tactics, which is in line with the objective reality at that time and is completely feasible.