Abstract: Satellite's on-board software is much more complex than before,so how to improve test efficiency of satellite software is very important for its quality.The effective testable software designing is the key for improving test efficiency of integrated on-board satellite software.Several testable designing methods were proposed including testable multi-layered software architecture used to restrict software defaults in a limited layer,task template in contract used to reduce the correlations between tasks,global status code series used to point out software flow dynamically,and task scheduling & stack records used to describe software flow statically.The data analysis indicates those testable designing methods mentioned are feasible and effective for improving test efficiency of satellite software.