Hi @Youjun Tang.. here is a short brief difference in both the technologies...
Mendix is a low-code platform and offers very quick development. Users feel the solution is robust and very flexible. Mendix presents a very decorative style with model-driven development that helps to validate flow. It has great mobile capabilities and the tooling is also very good. Some users feel the solution could be more scalable and tell us that there is some technical experience needed to properly use the solution. They feel it could be more user-friendly.
Microsoft PowerApps users like the flexibility of the solution and how simple it is to create an app from start to finish. Microsoft PowerApps offers the Model-driven or Canvas application-making platforms that make the entire process go very quickly. Microsoft PowerApps users tell us the solution can be a bit buggy, though, and needs some refinement to ensure things consistently run smoothly. The threshold limits could also be improved, as they can be very constricting and problematic.
Thanks for your rapid reply.
I'm interested in new knowledge. Keeping learning, COME ON.