From the perspective of the prototype development of intangible cultural heritage skill learning APP, the work aims to propose and construct the double diamond + PBL model of interactive design in this kind of prototype, to solve shortcomings of such prototypes in the improvement of users' critical thinking disposition. Aiming at the shortcomings of interactive design of the prototype of intangible cultural heritage skill learning APP in improving users' critical thinking disposition, on the basis of PBL (Problem-based Learning) mode which was widely demonstrated to be beneficial to improving critical thinking, a new interactive design prototype was developed by integrating the double diamond model of typical art design practice activities. Then, the method of quantitative research, namely the California Critical Thinking Disposition Scale, was used to pre-test and post-test 30 students participating in the experiment, and the mean score, median and normal distribution test scores were used to finally select Wilcoxon signed-rank test statistics to answer the research questions. The P value of critical thinking disposition was less than 0.05, and the P values of the other five sub-dimensions were greater than 0.05 except for the P value of open mind less than 0.05. According to the experimental results, the interactive prototype of intangible cultural heritage skill learning APP based on the double diamond + PBL model can improve the disposition of critical thinking, but can’t improve some sub-dimensions.