Many start-ups end up with the failure because they are unable to establish the effective business model. We use the organizational learning theory and network theory to study the mechanism of business model innovation for start-ups. Based on the 256 data of start-ups, the results of PLS structural equation model analysis show that both acquisitive learning and experimental learning can significantly promote the business model innovation. The formal network and informal network play different moderating roles on the relation of organizational learning and business model innovation.