The invention discloses a soil slope protection method and belongs to the technical field of environmental protection engineering. The soil slope protection method comprises the following steps: slope surface trimming including that a slope surface is leveled; curing agent preparation including that 16.8-22.91 parts of a cellulose curing agent solution, 18.18-24.79 parts of a macromolecular curing agent solution, 6.12-8.35 parts of an additive solution and 43.96-58.9 parts of water are uniformly mixed to form a curing agent; stabilized soil preparation including that 10 parts of slope soil and 2.5-4 parts of the curing agent are mixed; stabilized soil paving including that tap water is sprinkled onto the trimmed slope surface to wet the slope surface, and cured mud is paved on the slope surface; and stabilized soil conservation including that a stabilized layer is covered with a mulching film, and after grass seeds sprout, the mulching film is removed to obtain a stabilized layer formed by conservation. The soil slope protection method is more uniform in stabilization and higher in stabilization strength, allows large-area on-site construction and has higher applicability.