In this experiment, citrus fiber, beet fiber and agar were used to develop a low-sugar, high-fiber room-temperature fermented yogurt, and the texture and sensory quality of yogurt samples made with their combinations in different proportions were evaluated. Lactase and Sweety T-1, a mixed commercial starter culture of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus were used to completely decompose lactose in milk to produce glucose with higher sweetness, thereby improving the sweetness of low-sugar yogurt. The results showed that adding 3% citrus fiber, 0.2% agar and 1% beet fiber imparted good stability and high sensory score to low-sugar, high-fiber room-temperature fermented yogurt. Raw milk was inoculated 200 U/L Sweety T-1 with the addition of 1 600 BLU/L lactase and without the addition of any sugar or sweetener and was fermented at 42 ℃. After 12 h, lactose was completely decomposed, producing 2.5% glucose.