The invention discloses a multi-sensor starting method. A controller is used in the method and electrically connected with multiple detectors, and a sensor is arranged in each detector. The method includes that (1), the controller performs different address coding on the detectors sequentially; (2), when the controller is started, a power source output interface of the controller powers the detectors, and power sources of the sensors are turned off when a microprocessor of all detectors connected on a bus is powered on for the first time; (3), the controller orders each detector to turn on thesensor power source connected with the same according to its address coding multiplied with time delay of preset time. The method has the advantages that starting current can be lowered when sensor energy is started, and loss of electric energy on electric wires can be reduced.