This invention discloses one gas water compound dynamic force test method and its device, wherein, the test device comprises stable flow supply system, liquid supply system, reaction tar, temperature control system, stable exhaust system and data collection and process system. The said test method adopts continual flow reaction method to form or analyze dynamic speed, which comprises the following steps: supplying liquid; reaction tar volume adjusting; temperature controlling; stable flow supplying; stable voltage exhausting; reaction system achieving stable balance; data collecting and processing.