Leveling instrument for building detection

The utility model discloses a level ruler for building detection, which comprises a fixed ruler and a rotating ruler, the rotating ruler is rotatably connected to one end of the fixed ruler through a rotating assembly, the front surfaces of the fixed ruler and the rotating ruler are respectively provided with a horizontal level bubble and a vertical level bubble, and the front surfaces of the fixed ruler and the rotating ruler are respectively provided with a rotating groove. A rotating ring is rotationally connected into the rotating groove, an angle level bubble is arranged in the rotating ring, an angle indicating arrow is arranged outside the angle level bubble, and angle scale marks are arranged on the periphery of the rotating groove. The beneficial effects of the utility model are that when the inclination angle needs to be detected, the long edge of the fixed ruler or the rotating ruler is placed on a detection plane, the rotating ring rotates the angle level bubble to an absolute horizontal position