An electronic nose system for detecting quality of agricultural products mainly comprises a gas enrichment module mainly for collecting the low-concentration smell, a gas chamber and gas circuit module and a sensor array mainly for converting the smell signal into the electric signal, a sensor conditioning circuit and a data preprocessing module mainly for filtering, analog-to-digital converting and feature extracting of the output signal of the sensor array, an embedded system with data storage for identifying and judging the signal and a display and result output module, wherein the gas enrichment module consists of an adsorption tube filled with adsorbent, an electric heating wire and a temperature control device. The electronic nose system has the characteristics of small size, convenient carrying, high sensitivity of the system and wide application range of the system.