Information protection substation and priority response method thereof for master station command

The invention relates to an information protection substation and a priority response method thereof for a master station command. The application management module sends a channel state query message, and the communication module receives the channel state query message, a channel number, a channel state and a channel priority corresponding to a channel are written into a query confirmation message and the query confirmation message is returned if the priority level is not lower than the priority level and the channel state is a channel with a command to wait for execution; otherwise, the query confirmation message is not returned; if receiving the query confirmation message, the application management module sends an execution permission message; the communication module receives the execution permission message and controls the state of the corresponding channel to be switched to a state that a command is being executed; and if the query confirmation message is not received, the priority level is reduced s