The invention discloses a method and a system for carrying out ecological treatment on breeding wastewater from pig farms. The method comprises the following steps: A. carrying out solid-liquid separation; B. building a first-level front-end regulation and biomass purification treatment pond for treating the wastewater; C. building a second-level front-end regulation and biomass purification treatment pond for treating the wastewater; D. building a third-level front-end regulation and biomass purification treatment pond for treating the wastewater; E. building a first-level ecological wetlandfor treating the wastewater; F. building a second-level ecological wetland for treating the wastewater; G. building a third-level ecological wetland for treating the wastewater; H. building fourth-level ecological wetland for treating the wastewater; I. building a fifth-level ecological wetland for treating the wastewater; J. building a sixth-level ecological wetland for treating the wastewater; K. building a seventh-level ecological wetland for treating the wastewater; L. building an eighth-level ecological wetland for treating the wastewater; M. building an end enhanced treatment pond for treating the wastewater. The system consists of solid-liquid separation equipment, the first-level, second-level and third-level front-end regulation and biomass purification treatment ponds, the first-level, second-level and third-level ecological wetlands, the fourth-level ecological wetland, the fifth-level, sixth-level, seventh-level and eighth-level ecological wetlands, and the end enhanced treatment pond. The method is easy to implement, simple and convenient to operate and low in engineering construction cost; after the breeding wastewater is treated by the system, the contents of main pollutants such as chemical oxygen demand (COD), ammonia nitrogen, total nitrogen, phosphate and total phosphorus in the breeding wastewater are stably controlled to be within a certain range.