The present invention discloses a combustible gas detection system, comprising a background controller, a combustible gas detector, a fire detector, a fire extinguishing robot, an exhaust fan, a solenoid valve and an alarm device. The combustible gas detector comprises an explosion-proof shell, a charging interface, a power jack and a display screen; a power indicator light, a fault indicator light, a high report indicator light and a low report indicator light located at both sides of the display screen; an on/off key, an increase key, a decrease key and a query key at the bottom of the display screen; detection parts symmetrically disposed on the explosion-proof shell; a circuit board fixed inside the explosion-proof shell; and a power supply module, a communication module, a control module and a recording module on the circuit board. The control module comprises a self-test unit, a temperature compensation unit, an A/D conversion unit, a time detection unit, a first judgment unit, a second judgment unit and a control unit. With simplified keys, the combustible gas detection system is convenient to operate and is able to detect combustible gas and also deal with harsh conditions, thereby achieving high practicability.