In this paper the life cycle theory was applied to assess the environmental impact of three straw-recycling modes in farmlands in the Chengdu Plain. The results showed that the total CO₂ equivalence of greenhouse gas(GHG) emissions from the rice-wheat rotation with mushroom residues applied(the FR mode) was 1.44×10⁷ g CO₂-eq, and was the lowest amount among the three straw recycling modes. While, the CO₂ equivalence of GHG emissions from the rice-wheat rotation fertilized with crop straws applied(CFS mode) was the highest. Compared with the traditional agricultural production mode (chemical fertilizer application (CF mode)), the environmental acidification potentials of the CFS and FR modes were decreased from 6.44×10⁴ g SO₂-eq to 3.10×104 g SO₂-eq and to 1.21×104 g SO₂-eq, and decreased by 51.85% and 81.21%, respectively. The water eutrophication potentials of the CFS and FR modes were also decreased by 24.21% and 52.28%, respectively. The sequence of the soil toxicity potentials were in the order of CF