Abstract: In order to study the influence of different microstructures on the plane blackbody reflectance, 40 kinds of plane blackbody samples with surface microstructures composed of different cone gear types (square cone and circular cone), height and density were designed. The same process was adopted on the samples surface, and the same type of surface absorption coating was sprayed to reduce the surface reflection. The reflectance of the samples in the visible and near-infrared bands was measured by the spectrometer. The measurement results show that the microstructure can reduce the reflectance from 1.4% in the plane state to nearly 0.4%. When other conditions are consistent, the higher the height of the cone gear and the denser the cone gear, the lower the reflectance of the plane blackbody; different cone gear types have no significant effect on the reflectance; compared with the simulation value obtained by the Tracepro, the higher the height of the cone gear, the denser the cone gear surface, the greater the relative error, and the relative error is in the range of 10% ~ 65%.