The invention discloses an ignition and fire detection circuit based on a BOOST principle and a gas wall-hanging stove. The ignition and fire detection circuit comprises a controller and an ignition module; the ignition module comprises a boosting and detecting unit; and the boosting and detecting unit is connected with an external direct-current power source to be used for maintaining an ignitionpower source at a set voltage, and meanwhile a detected ignition voltage of the ignition power source is fed back to the controller. The ignition and fire detection circuit based on the BOOST principle and the gas wall-hanging stove eliminate the inductance squealing problem, a high voltage of the ignition power source is isolated from a controller chip, and the safety of the circuit is improved;the ignition module and a flame detection module share one boosting circuit, and the circuit cost is lowered; and a comparator is adopted for outputting a flame parameter signal, an I/O port connected with a flame detection signal is changed into a common detection port from an analog (AD) detection port, a detection signal is more accurate, and difficulty is greatly lowered during hardware design and software programming.