Looking at the course of educational development in developing countries, nongovernmental organizations (NGOs), nonprofit organizations (NPOs), and volunteers have played a significant role in increasing educational resources in underdeveloped areas and moving educational resources to a balanced state. This study used a mixed-methods approach to investigate the underlying factors affecting volunteer teaching activities of Chinese college students. Data were collected from multiple resources using a self-developed questionnaire and semi-structured interviews. It was found that volunteer teaching activities of college students in China were affected by five key factors including motivation ambiguity, confused identity, unspecialized service, weak incentive mechanism, and a lack of supervision mechanism. In addition, exploratory factor analysis revealed that skills, activity experience, and volunteer performance were significantly correlated with the college students' willingness to participate in volunteer teaching. Informed by the data, we proposed some tentative solutions to solve the challenges and dilemmas from the perspective of consciousness training, systematism cultivation, concept guidance, and the establishment of incentive and supervision mechanism.