A method for mounting an interlock module between two contactors (100, 200), wherein the interlock module is configured to, in an assembled state, to ensure that in the case where one of the two contactors (100, 200) is switched on, the switching on of the other of the two contactors (100, 200) is blocked, the method comprises at least the following steps: step 1: providing two contactors (100, 200), including a first contactor having a first mounting surface and a first movable iron core assembly and a second contactor having a second mounting surface and a second movable iron core assembly, and placing the first contactor and the second contactor side by side with a gap therebetween, so that the first mounting surface faces the second mounting surface, step 2: providing the interlock module comprising a first slider, a second slider and a housing formed separately from the first slider and the second slider, an interlocking portion being mounted in the housing for interacting with the first slider and the second slider to generate an interlocking effect, a side of the housing is provided with a notch, and the housing is provided with a first receptacle and a second receptacle communicating with the notch, the first receptacle being used for receiving the first slider through the notch, and the second receptacle is used for receiving the second slider through the notch, the first slider is provided with a first pin protruding relative to a first body of the first slider for cooperating with a first mounting hole in the first movable iron core assembly of the first contactor, the second slider is provided with a second pin protruding from a second body of the second slider for cooperating with a second mounting hole in the second movable iron core assembly of the second contactor, the first receptacle is defined at least by a first outer side of the housing in which a first channel is provided to allow the passage of the first pin, the second receptacle is defined by at least a second outer side of the housing which is opposite to the first outer side and in which a second channel is provide to allow the passage of the second pin, step 3: connecting the first slider to the first movable iron core assembly of the first contactor through the first mounting surface, step 4: connecting the second slider to the second movable iron core assembly of the second contactor through the second mounting surface, step 5: assembling the housing to the first slider and the second slider, step 6: removably fixing the housing, wherein the order of step 3 and step 4 can be interchanged. step 1: providing two contactors (100, 200), including a first contactor having a first mounting surface and a first movable iron core assembly and a second contactor having a second mounting surface and a second movable iron core assembly, and placing the first contactor and the second contactor side by side with a gap therebetween, so that the first mounting surface faces the second mounting surface, step 2: providing the interlock module comprising a first slider, a second slider and a housing formed separately from the first slider and the second slider, an interlocking portion being mounted in the housing for interacting with the first slider and the second slider to generate an interlocking effect, a side of the housing is provided with a notch, and the housing is provided with a first receptacle and a second receptacle communicating with the notch, the first receptacle being used for receiving the first slider through the notch, and the second receptacle is used for receiving the second slider through the notch, the first slider is provided with a first pin protruding relative to a first body of the first slider for cooperating with a first mounting hole in the first movable iron core assembly of the first contactor, the second slider is provided with a second pin protruding from a second body of the second slider for cooperating with a second mounting hole in the second movable iron core assembly of the second contactor, the first receptacle is defined at least by a first outer side of the housing in which a first channel is provided to allow the passage of the first pin, the second receptacle is defined by at least a second outer side of the housing which is opposite to the first outer side and in which a second channel is provide to allow the passage of the second pin, step 3: connecting the first slider to the first movable iron core assembly of the first contactor through the first mounting surface, step 4: connecting the second slider to the second movable iron core assembly of the second contactor through the second mounting surface, step 5: assembling the housing to the first slider and the second slider, step 6: removably fixing the housing, wherein the order of step 3 and step 4 can be interchanged.