The poloidal field (PF) power supply is an important subsystem of the EAST (Experimental Advanced Superconducting Tokamak as the device status detection and protection are essential. The PF power supply monitor system is based on the Experimental Physics and Industrial Control System and the human machine interface is the Control System Studio (CSS). The alarm is a plugin of CSS, used to help operators take correct action at the correct time. This technical note creates the alarm system, including server, client, Java Message Service interface, and relational database and configures the alarm attribute and sets the action for all variables that may trigger the alarm. When the alarm is triggered, the system goes into fault mode, the alarm server sends mail or pops up a window automatically to prompt operators, and some actions may be executed automatically to protect the device. Then operators solve the fault according to the guidance and the system returns to normal, realizing device status monitoring and protection in real time. The EAST experiment shows the alarm system has better function and stable performance.