To determine when artillery stuck because of the phenomenon of cartridge problem or artillery problem, analysis the cause of stoppage and research the testing method, there are: calculates the extraction force basis the electric current of strain gauge. When stoppage happens, compares it with artillery actual extraction force, tests the stoppage force, if former is less than later, shows cause of stoppage from artillery, whereas, reveals cause from excessive stoppage force of cartridge case. Result shows that the testing method is simple and reliable, data is accurate, providing important value for theory and practice.