The thermal vacuum environment-simulating test provides a way of simulating surface heating load of aircrafts. In order to simulate the high vacuum and high heat, a set of thermal vacuum environment-simulating controlling and detecting system is established. The quartz radiation heating system is utilized as the heating source. High heat and temperature will damage the spacecraft and may even harm the safety of the spacecraft. Therefore, the covering methods of signal cables with thermal insulating materials are evaluated based on the thermal vacuum environment-simulating test. Experimental results indicate that the aluminized film outperforms alkali-free glass fiber in cable protection, which satisfies the thermal control requirements of spacecraft. Thus, this kind of test can be employed in demonstrating the thermal protection scheme within thermal environment.