A pluggable connecting device for contactors, the contactor comprising: a housing; a coil framework located in the housing and having a first connecting piece and a second connecting piece configured to be opposite each other; and an electromagnetic coil wound on the coil framework, two ends of the electromagnetic coil being electrically connected to the first connecting piece and the second connecting piece respectively, wherein the pluggable connecting device comprises an insulation connection member and a first conducting element and a second conducting element fixedly connected to the insulation connection member; the first conducting element has an insertion end and a wiring end configured to be opposite each other; the second conducting element has an insertion end and a wiring end configured to be opposite each other; the insertion end of the first conducting element and the insertion end of the second conducting element are configured to be pluggably connected to the first connecting piece and the second connecting piece of the contactor respectively; wherein the insertion end of the first conducting element has two opposite first engagement portions (17214, 17215); an insertion slot is defined between the two first engagement portions (17214, 17215); the insertion end of the second conducting element has two opposite second engagement portions (17214, 17215); an insertion slot is defined between the two second engagement portions (17214, 17215); characterized in that the two first engagement portions (17214, 17215) each have one protrusion (17211, 17212), the protrusions being located away from each other, and the two second engagement portions (17214, 17215) each have one protrusion (17211, 17212), the protrusions being located away from each other. a housing; a coil framework located in the housing and having a first connecting piece and a second connecting piece configured to be opposite each other; and an electromagnetic coil wound on the coil framework, two ends of the electromagnetic coil being electrically connected to the first connecting piece and the second connecting piece respectively, wherein the pluggable connecting device comprises an insulation connection member and a first conducting element and a second conducting element fixedly connected to the insulation connection member; the first conducting element has an insertion end and a wiring end configured to be opposite each other; the second conducting element has an insertion end and a wiring end configured to be opposite each other; the insertion end of the first conducting element and the insertion end of the second conducting element are configured to be pluggably connected to the first connecting piece and the second connecting piece of the contactor respectively; wherein the insertion end of the first conducting element has two opposite first engagement portions (17214, 17215); an insertion slot is defined between the two first engagement portions (17214, 17215); the insertion end of the second conducting element has two opposite second engagement portions (17214, 17215); an insertion slot is defined between the two second engagement portions (17214, 17215); characterized in that the two first engagement portions (17214, 17215) each have one protrusion (17211, 17212), the protrusions being located away from each other, and the two second engagement portions (17214, 17215) each have one protrusion (17211, 17212), the protrusions being located away from each other.