In automatic real-time embedded software testing, the design and realization of test description execution system is one of the key problems. Based on object-oriented programming thought, an execution engine oriented automatic real-time embedded software test description language (RT-ESTDL) was designed and realized. The test description driven real-time embedded software testing process was studied. And then, the general design scheme of the execution was put forward. The compiling and the execution process of the engine, including the hash function and its conflict resolution and the test description execution process based on segment-based rate monotonic scheduling (SBRMS) were brought forward. The evaluation and analysis result of the efficiency indicates that the engine can meet the requirements of real-time and concurrency in real-time embedded software testing by controlling the test description scale and the concurrent execution number reasonably, and has good transportability.