Online learning has become one of the directions for major universities to achieve educational reform, and the online learning ability of college students is the key to the effectiveness of online education. Based on the Biggs3P theory, an online learning strength table was constructed, and factor analysis was used to construct college students' online learning ability. Regression analysis was conducted to identify the influencing factors of online learning ability and determine the mediating role of deep learning orientation. The empirical results indicate that multiple factors in the online learning environment, including but not limited to learning resources, student interaction, teacher support, and learning evaluation, all have varying degrees of positive effects on college students' deep learning orientation. Among them, the learning evaluation and teacher support of online learning have a strong influence, while the technical usability of online learning platforms has the weakest influence. In response, suggestions are proposed to enrich the construction of online learning resources, enhance the interactive experience of online learning students, strengthen the diversified development guided by online teachers, and build a multi-dimensional online learning evaluation mechanism.