The invention provides an electricity generation device making use of traffic loads. The electricity generation device comprises a plurality of piezoelectric structure units which are embedded in a road surface layer. Each piezoelectric structure unit comprises an upper protecting layer and a lower protecting layer. A first elastic layer, a piezoelectric plate and an elastic array layer are sequentially arranged between each upper protecting layer and the corresponding lower protecting layer from top to bottom. The first elastic layers are arranged transversely. Each elastic array layer comprises a plurality of second elastic layers which are arranged longitudinally, and the elasticity moduli of the second elastic layers are gradually decreased or increased. The piezoelectric structure units are connected with a power supply control box through conducting wires, and the power supply control box is connected with electric equipment. According to the electricity generation device, the piezoelectric structure units are embedded in the road surface layer, mechanical energy produced by the traffic loads is converted into electric energy under the forward piezoelectric effect of piezoelectric materials, and the electric energy is supplied to the electric equipment or stored. No external energy input is needed in the collecting and conversion process, self-sufficiency is achieved completely, no pollution will be generated, no land resource is wasted, and electric energy transmission cost and loss are reduced.