Aiming at whether the strong earthquake can be predicted and how to predict, the brittle failure theory of multiple locked patches in a seismogenic fault system is developed. The results indicate that the seismogenic process of strong earthquake obeys a simple mechanic law. The seismogenic mode can be classified into the following four types: large-small-large earthquake magnitude mode in a siesmogenic period, continuously rising large earthquake magnitude mode in an earthquake sequence, quickly and continuously fracturing mode of multiple locked patches and standard earthquake mode.