Digital platform niche creation is the ability of a digital platform to increase meaningful diversity by creating new and valuable products and services. From the accessibility design perspective of digital platform governance, a theoretical model on digital platform niche creation is developed and tested. Two antecedent variables are platform openness and platform incentives, and one outcome variable is platform performance. The hypotheses were tested using survey data from 252 domestic transactional digital platforms in China, and partial least squares analysis-structural equation modeling (PLS-SEM) was used for analysis. The findings show that not only platform openness and platform incentives have a positive impact on niche creation, but niche creation also has a positive impact on platform performance.