Abstract: Doris Lessing is a famous woman writer in Britain. Her space fictions, Canopus in Argos:Archives, are very important works in her literary creation. Her space fictions, The Marriages between Zones Three, Four, and Five and The Sirian Experiments reflect the ecological destruction inflicted by the colonial empires on the colonies. This paper studies these two works from the perspective of postcolonial ecocriticism. By analyzing the destruction of the social and cultural ecology and natural ecology inflicted by the colonial empires on the colonies, it warns that today's human beings should attach great importance to the overall interests of ecology to build a harmonious ecological world.