In order to solve the problem of identification of fish storage methods (chilled and frozen), a technique for rapid detection of fish storage methods was proposed based on a single-chip computer system and biological impedance. The relative changing rate of impedance of chilled and thawed crucian and carp at the signal frequency of 1kHz and 16kHz was measured and analyzed. The results showed that the relative changing rate of impedance of chilled fish was more than 100%, while the relative changing rate of impedance of thawed fish was less than 100%. Arduino microcontroller system, resistors and high frequency AC voltage sensors were used to build circuit detection system. Firstly, the fish was connected to the detection system and the voltage information across the resistor and the voltage information across the fish were obtained when the AC signal frequency was 1kHz and 16kHz, respectively. Then, the relative changing rate of the impedance of the fish body at the signal frequency of 1kHz and 16kHz was calculated. Finally, the relative changing rate of impedance was used to identify chilled fish and thawed fish, and the detection results was output on the display terminal. This technology had good performance, simple and convenient operation, no damage to the fish during the detection process, and the identification process was accurate and efficient, and the detection accuracy rate can reach 95%. This technology solved the problem of difficulty in identifying chilled fish and thawed fish, and provided a idea for the detection of fish storage methods.