The invention discloses a class of diamond-shaped nano unit cell aromatic hydrocarbon and an A2+B2 type Friedel-Crafts lattice synthesis method thereof, and belongs to the fields of organic photoelectric material preparation and nanotechnologies. In the invention, the diamond-shaped nano unit cell aromatic hydrocarbon is one class of nano-scale macromolecular closed-loop compounds with clear edges, a regular structure (an approximate geometric diamond shape) and four extendable arms, wherein a general structural formula of the diamond-shaped nano unit cell aromatic hydrocarbon (a planar structure on the left side and a three-dimensional structure on the right side) is as shown in the specification. The synthesis method is based on the Friedel-Crafts reaction, and the diamond-shaped nano unit cell aromatic hydrocarbon is synthesized by using an A2+B2 type synthon. Through the reasonable design of a synthesis route, the Friedel-Crafts reaction having the advantages of mature conditions,high selectivity, high yield, easy and convenient operation, environmental friendliness and the like is used to construct the diamond-shaped nano unit cell aromatic hydrocarbon, thereby avoiding the problems of high toxicity of heavy metal catalysts used, complicated operation steps, environmental pollution and the like in a traditional synthesis process of a macrocyclic compound.