Nondestructive measuring method for leaf area of broad leaved plant

The invention discloses a nondestructive measuring method for the leaf area of a broad leaved plant, and aims to solve the problem that a measured leaf is destroyed in the prior art. The nondestructive measuring method comprises the following steps: 1, measuring an area S1 of a white board through a ruler, wherein S1 is equal to 10cm*10cm, namely 100cm ; 2, photographing the white board and themeasured leaf; 3, cropping photos; 4, respectively weighing the picture weight of the white board G1 and the picture weight of the measured leaf G2; 5, calculating the real area S2 of the measured leaf, wherein S2 is equal to S1*G2/G1; 6, weighing the picture weight of the measured leaf when a part of the measured leaf is illuminated; 7, calculating the relative total area S3 of the measured leafwhen the part of the measured leaf is illuminated; and 8, calculating the relative area S4 of the illuminated part of the leaf, wherein the relative area S4 of the illuminated part of the leaf is obtained through a formula (S4/S3 is equal to G4/G3); and S4 is equal to G4/G3*S3.