This paper use Laboratory Virtual Instrument Engineering to build an automatic measurement of Agilent HP4192A impedance analyzer and parameter extraction platform. Firstly, the impedance characteristics of piezoelectric ceramic transducer is measured and plotted. According to the model theory of piezoelectric ceramic transducer, the model parameters of the piezoelectric ceramic transducer's equivalent circuit are extracted. An impedance matching transformer is designed to improve the transmitting efficiency according to matching theory. In general, this impedance measurement platform can be used to measure the impedance of the common electric components. Specially, the platform is applied to the model parameter extraction and designs of piezoelectric transducers. Many advantages such as low-cost, high efficiency, high reliability and easy to carry is provided by this automatic impedance measurement system.