Integration of security systems including CCTV, Intruder Alarm, Access Control, fire alarm etc. are required for high security projects. Before security system integration, they have to consider the possibility of software integration, then the integration way of hardware. Now, most integrated software are made according to standard of ONVIF or PSIA. Engineers need to consider the consistency of each sub systems communication protocol. That include consistency of operation system(Both windows and Linux are availble), data transfer format. After integration of software, it is more easy to integrate hardware. But it still requires reserved interface, multiple network module, linkage module etc. for the devices. There are some details of integration such as more reasonable and safety interactive design for each sub-system, AC /DC power switch for devices.