Vernier height gauge for high-precision levelness measurement and measurement method thereof

The invention discloses a vernier height gauge for high-precision levelness measurement and a measurement method thereof. The vernier height gauge comprises a gauge body, a vernier, a spirit bubble, a mounting seat, a first perpendicularity adjusting device and a second perpendicularity adjusting device, length scales are arranged on the ruler body; the ruler body is vertically arranged; the measuring head is arranged at the bottom of the ruler body and used for being tightly attached to a measuring point during measurement; the vernier is sleeved on the ruler body in a sliding manner; the spirit bubble is mounted at the top of the ruler body; the mounting seat is arranged on a measuring surface; the first perpendicularity adjusting device and the second perpendicularity adjusting device are both installed on the installation base and used for adjusting the perpendicularity of the ruler body in the two directions. In the application, the levelness of the ruler body can be adjusted through the cooperation of t