To eliminate technical defects of piezoelectric transducers used in road engineering, piezoelectric stack harvesting unit structures being applicable to road power generation were preferably selected and their sizes were optimized, 8 piezoelectric stack harvesting units used in road engineering were prepared. Their structural strengths were evaluated by means of mechanical property tests. The test fixtures for piezoelectric harvesting units were developed, and the anlog test systems for electricity generating performance were constructed. The electricity generating performance of piezoelectric harvesting units was studied, the electrical energy output effect of power pavement’s small-size specimens were measured. The results showed that the structural strength of the piezoelectric stack harvesting units prepared is good to meet the requirements of power pavement’s construction and working; within the test range, magnitude of load, loading frequency, thickness of piezoelectric ceramic piece and layer number of stack are positively correlated to electricity generating performance of piezoelectric harvesting units; the maximum open circuit voltage and the maximum power of piezoelectric stack harvesting units with monolithic thickness of 1.0mm can reach 37.8V and 183.2 mW, respectively; the energy output of the typical power pavement’s small specimen is 11.06mW, so it has an ideal application prospect.