The invention discloses a side slope reinforcing construction method by combining vegetation with microorganisms and a thin-walled steel tube for construction. The construction method protects a slopejointly by using clover and bermuda grass and injects bacillus pasteurii and a bonding liquid into soil, wherein the bacillus pasteurii and the bonding liquid are injected repeatedly every 6-8 days for 30-40 days. The clover and common bermuda grass are selected to protect the slope jointly, and meanwhile, and a product for microbial soil fixation is calcium carbonate which is good in integrationto a soil mass matrix, so that a formed bonding material is high in strength, and the shear strength of the soil mass of the side slope can be improved obviously. In a stage that the common bermuda grass does take roots, the side slope is reinforced, and meanwhile, the binding liquid contains a lot of urea to provide a lot of chemical fertilizer elements to the common bermuda grass, so that the growth period of the common bermuda grass can be shortened to 35 days, the side slope exposure time is further shortened, and the risk of collapse of the side slope is reduced. The invention also provides the thin-walled steel tube for construction, has the characteristics of being low in cost, easy to manufacture and convenient to construct, and brings convenience to quickly cure the soil mass inthe side slope.