The parallel-plate electrode technique is widely used to evaluate physico-chemical properties of agricultural products because of its high precision, convenience and non-destructiveness. Electrical parameters, such as impedance Z, equivalent capacitance C, admittance Y, quality factors Q, phase angle θ and dielectric constant ε that are detected by this parallel-plate electrode technique can be used to evaluate a food material’s physico-chemical properties, physiological status and quality. Various factors can affect these electrical parameters. Some examples include the environmental factors of temperature and pressure; the measuring conditions of voltage and frequency; and the internal factors of water content, salt content, ripeness, freshness and shape. Therefore, it has been established the principle of parallel-plate measurement, and demonstrated its applications; namely, in the nondestructive maturity detection of fruits and vegetables, the quality testing of liquid food and the determination of the physico-chemical components of other food products. This review provides reference for future research and applications in food quality determination using the parallel-plate electrode technique.