The invention relates to a comprehensive security monitoring system for a substation. The comprehensive security monitoring system comprises a perimeter security monitoring module, a running equipment temperature online monitoring module, a security measurement and control host and an information management module, wherein the perimeter security monitoring module comprises a first microprocessor and a laser fence; the laser fence is connected with the first microprocessor; the perimeter security monitoring module is used for detecting intrusion information in the perimeter of the substation; the running equipment temperature online monitoring module comprises a second microprocessor and a temperature measurement unit, which are connected with each other; the running equipment temperature online monitoring module is used for monitoring a real-time temperature of running equipment; the security measurement and control host is connected with the first microprocessor and the second microprocessor in a wireless communication manner and is used for receiving and processing the intrusion information and temperature information; and the information management module is connected with the security measurement and control host through an optical fiber network, and is used for receiving the information of the security measurement and control host and achieving information sharing. Compared with the prior art, the comprehensive security monitoring system has the advantages of being integrated in system, open in interface, convenient to maintain and the like.