The measurement error due to the blocking effect is discussed when the anemometer is tested in the wind-tunnel experiment, whose purpose is to explore an arithmetic of blocking correction coefficient with universal significance. Taking the book named as “test in the wind-tunnel of low-speed” as a basis, according to the country′s measuring amount value, the solid cylindrical blocking revision method in the wind-tunnel of two dimension is transplanted, derived, and became a method with the wind speed transducer blocking coefficient, so mathematical measurement model is set up,and then,the mathematical measurement model is verified to the wind speed transducer of the automatic weather stations in Guangdong Province, and the ideal result is obtained.