The invention relates to a laser-based alkali metal air chamber low-noise heating method. An atom magnetometer and an alkali metal air chamber in an atomic gyroscope are heated through laser. Through heating laser far detuning pumping laser and detecting laser, the alkali metal air chamber is heated, and high density alkali mental atomicity is obtained through specific temperature controlled by closed loop feedback. Meanwhile, because heating electrical current is not introduced to a gauge outfit by laser heating, magnetic field interference caused by heating can be eliminated fundamentally, and an all-optical SERF atom magnetometer is obtained. Besides, because a heating film and a power supply introduced by non-magneto electric heating are avoided, and a bulky oven introduced by hot-air heating is also avoided, the size of the magnetometer can be reduced significantly, and miniaturization of the SERF magnetometer can be realized, and a foundation is laid for engineering application of the SERF magnetometer.