High-precision sun exposure sensor and measuring method thereof

The invention relates to a high-precision sun exposure sensor and a measuring method thereof. The high-precision sun exposure sensor comprises a first photoelectric tube, a second photoelectric tube and a third photoelectric tube which are arranged in a coaxial mode. A shading cylinder is provided with upper portion incidence windows and lower portion incidence windows, wherein the upper portion incidence windows are evenly and symmetrically distributed on the upper portion of the shading cylinder, the lower portion incidence windows are evenly and symmetrically distributed on the lower portion of the shading cylinder, the number of windows included in the upper portion incidence windows is consistent with that of windows included in the lower portion incidence windows, and the windows of the upper portion incidence windows and the windows of the lower portion incidence windows are distributed on the shading cylinder in a staggered mode so that diffuse radiation received by the second photoelectric tube throu