Abstract: To further expand the variety of oat milk products and develop an oat plant-based yogurt (OPY) without animal ingredients, this study used whole oat flour as raw material to prepare oat milk through enzymatic hydrolysis, inoculated with commercial fermentation culture to prepare OPY. The production was optimized using single-factor experiments and response surface methods, and the properties of OPY was analyzed. The results showed that the optimal production parameters for OPY were as follows: solid-liquid ratio was 1:3.9 (g:mL), culture addition ratio was 0.17% (based on the addition ratio of whole oat flour), and fermentation time was 7 hours. Under these conditions, the sensory score of OPY was 86.33±0.58, the β-glucan content (dry basis) was 8.37±0.20 mg/100 mL. Compared to stirred yogurt (SY), the titratable acidity and fat content of OPY decreased by 32.1% and 15%, respectively. The water holding capacity and total solid content of OPY increased by 41% and 34.76%, respectively. The texture and rheological analysis showed that the cohesiveness (0.71±0.00), springiness (0.83±0.00), elastic modulus and viscosity modulus of OPY were significantly higher than that of SY. After enzymatic hydrolysis and fermentation, OPY retained β-glucan, and had better rheological properties. In addition, several physicochemical indicators and nutritional components of OPY were better than those of SY, indicating that the process optimization had been successful. This study has high reference value for the actual production of OPY, and also provides new ideas for the development of fermented oat beverages.