Abstract:Citrus is an important fruit crop in China，and its fruit quality is one of the key factors affecting consumer purchase and determining the market value. Therefore，the testing of citrus fruit quality is particularly important. Manual testing is inefficient and easily affected by subjective factors，failing to meet the requirements of non-destructive testing in the modern fruit market. Therefore，emerging technologies with good objectivity and high degrees of automation have become the research focus of fresh fruit quality testing. The latest technologies and research progress in the testing of citrus fruit defects were summarized，and the common types of defects in citrus fruits and their causes were introduced. Furthermore，the existing non-destructive testing technologies were compared regarding their principles，advantages，and disadvantages. Finally，the future development directions were proposed，with the aim of providing a reference for non-destructive testing of citrus fruit defects.