Safety guardrail for building construction

The invention discloses a safety guardrail for building construction. The safety guardrail comprises two end vertical parts and at least two groups of shear frames, wherein the left and right ends of the shear frames are respectively connected with the two end vertical parts; in all the shear frames, the same middle vertical part I is connected to a hinge point I which corresponds up and down, and the same middle vertical part II is connected to a hinge point II which corresponds up and down; concave sleeves and base parts for supporting are further arranged on the two end vertical parts; vertical waist-shaped slots I are formed in the front and rear side surfaces of the two end vertical parts; the concave sleeves are in a vertical state and sleeve the end vertical parts; insertion columns matched with the waist-shaped slots I are arranged on the inner walls of the concave sleeves; when the insertion columns are propped against the top ends of the waist-shaped slots I, the concave sleeves can rotate around th