Features: it embodies the integrity and comprehensiveness of the relationship between man and nature, regards nature, society and man as a composite ecosystem, and emphasizes its overall movement law and comprehensive value role to man; Break through the theoretical framework and methodological limitations of studying single natural phenomenon or single social phenomenon respectively in the past; It is required to limit man's transformation of nature to the limits permitted by the earth's ecological conditions, and to oppose the blind tendency of unilaterally emphasizing man's rule over nature and endless pursuit of material enjoyment.