In response to possible fire, SF6 leakage, and inbound robbery in the substation, this article designs an IoT intelligent security system based on the SPCE061A single-chip microcomputer that sends mobile phone text messages via GPRS to complete substation alarms. The security system is mainly composed of three parts: the main control unit (Lingyang MCU SPCE061A), the acquisition (temperature, smoke, door sensor) unit, wireless GPRS (MC35) network alarm unit. SPCE061A is the main control part, and uses temperature, smoke, door sensor and other sensors to collect information, built-in A / D to complete data collection, and directs MC35 to complete wireless transmission, and sends alarm messages to multiple people in the form of mobile phone short messages in time. Multi-point automatic interconnection of mobile phones. The experimental results show that the system is sensitive in response speed, no delay in alarms, high reliability, simple wiring, low cost, and broad application prospects. It can be used not only in substations, but also in residential buildings, shopping malls, warehouses and other occasions .