Since the 18th National Congress of the Communist Party of China, the central government has formulated a series of policies for government data opening, encouraging local governments to explore developing strategies. With the deepening of local government data opening practice, the differentiation of data opening performance among local governments are becoming increasingly prominent. We aim to explain how the performance difference is formed under the same level of stimulus by the central government. Based on technology, organization and environment dimensions of classic TOE framework, combined with resource-based theory and performance championships theory, we build the “push-pull model” to analyze the mechanisms underlying local government data opening. The qualitative comparative analysis shows that the three forces of technology (push), organization (push) and environment (pull) together constitute the “push-pull” system for the performance of government data opening. Technology dependence, local financial support and intergovernmental competition are the core mechanisms underlying the performance of local government data opening, and between the pushing and pulling forces the performance differential has gradually emerged and has become increasingly explicit.