Stellar flares are sudden bursts of energy as a result of magnetic activity. We have used light curves from the TESS 20 second cadence survey from 2020 to 2023 to detect flare events, and determine their properties. By means of repeated fitting to distinguish stellar background light curves and flare events, we detected 32978 flare events associated with 5463 flaring stars. Furthermore, we cross-matched our samples with the Gaia and SDSS surveys, and obtained additional stellar parameters for determination of relationships between stellar and flare properties. We found that the durations of 55% of the studied flares were less than 8 minutes. Flare energies of the TESS 20 second cadence are usually smaller than those obtained by TESS 2-min cadence data. We identified 28425 flare events associated with4,784 flaring stars. The relationship between flare energy and duration for both giant and main sequence stars display a consistentV-shaped distribution. There is a positive correlation trend on both sides with 10^34^erg. Stars with lower effective temperature and mass generate more frequent flare events. In summary, it is necessary to detect more flare events with higher time resolution and our flare samples with 20-second cadence are important for discovering additional new properties.