The research focus of this book is the growth limit of coal production, and the "growth limit theory" proposed in the Research Report "growth limit" of the club of Rome "is an important theoretical basis of this book. "Growth limit theory" has put forward pessimistic expectations for the development of the world economy, but when we study the supply of fossil energy in the world and the supply of coal in China, the situation is not optimistic. Malthus's theory of population more than 200 years ago is also a theory of pessimistic expectations for the future of the world. It has a certain degree of homogeneity with the theory of growth limit, and also indicates the future growth limit. Therefore, we review and comment on Malthus's population theory.