Abalone are of significant economic importance in the marine shellfish market in China. In order to examine feeding characteristics and formulate a model of gastrointestinal evacuation for Haliotis discus hannai, H. gigantea, and H. discus hannai ♀ × H. fulgens ♂, fecal output after intake of feed labelled with chromium sesquioxide (Cr2O3) was subjected to uninterrupted monitoring for 72 h. Feed consumption levels of H. discus hannai, H. gigantea, and H. discus hannai ♀ × H. fulgens ♂ were seen to harbor a circadian rhythm. Over 90% of the feed intake occurred between 20:00 and 04:00, and fecal output of H. discus hannai, H. gigantea, and H. discus hannai ♀ × H. fulgens ♂ was continuous over the experimental period. The cosine fitting peak phases of fecal output of H. discus hannai, H. gigantea, and H. discus hannai ♀ × H. fulgens ♂ appeared at 09:07, 08:46, and 08:24, respectively, all about 9 h after the appearance of each feeding peak. Based on the measured Cr2O3 content in feces, about 70% of the gastrointestinal evacuation of the labelled feed occurred 12–24 h after consumption. The time-dependent variation of the percentage evacuated of three abalone species agrees well with the logistic model (R2 > 0.99); H. discus hannai, H. gigantea, and H. discus hannai ♀ × H. fulgens ♂ evacuated 50% of the feed within about 19 h, and 95% was evacuated at 32.99, 30.09, and 29.96 h, respectively. In this work, a non-destructive method was used to accurately measure the time required for the gastrointestinal evacuation of abalone, provided that abalone could ingest feed without fasting. This work not only enriched the basic knowledge of abalone’ digestive physiology, but also provided a theoretical reference for developing reasonable feeding strategies.