[Question]TestCase distributed execution？

When a large number of test cases with long execution times are required, can FitNesse test cases support distributed execution?

I'm not sure what you mean exactly, but you can (of course) run different (sub) suites on different processes/machines. So for instance if you have a test set below a suite A, consisting of suite A.B and suite A.C you can have one process that executes A.B and another running A.C.

And there is also a feature to partition a single suite into parts that you can then run in different processes. See http://fitnesse.org/FitNesse.FullReferenceGuide.UserGuide.WritingAcceptanceTests.TestSuites.SuitePartitioning

For my own test projects I created a small helper to create an overview page combining the test results of multiple test jobs (HtmlReportIndexGenerator).

My project also offers a sample pipeline (for GitLab) partitioning a test set first in an acceptance and example test suite (different suites in the wiki) and the splitting each of these suites based on the historic run times of each test (8 partitions for the acceptance tests and 6 for the example tests). The test results of all partitions are then combined into single reports (sample example report). Admittedly this is a bit of a complex setup, but to me this does show FitNesse tests can be run in a distributed fashion to speed up total execution times.