The invention provides a conductive thermoplastic elastomer and a preparation method thereof. The thermoplastic elastomer includes following blended components: a. thermoplastic resin; b. rubber particles having crosslinking structures; c. a conductive filling material; and d. low-melting-point metal. Gel content in the component b is, by weight, 60% or more than 60%. An average particle size of the rubber particles is 0.02-1 [mu]m. The component c is not melted at a processing temperature of the thermoplastic resin. The component d is at least one of a single-component metal and a metal alloy. A melting point of the component d ranges from 20-480 DEG C and is lower than the processing temperature of the thermoplastic resin. A weight ratio of the component b to the component a is more than 30:70 and is lower than 75:25. The conductive polymer composite material is low in filling amount of the conductive filling material and the low-melting-point metal, is excellent in conductive performance, can be prepared through a melt blending method, can be used for manufacturing electronic production devices and tools which have an anti-static function and an electromagnetic wave interference resistant function and is of a dust-free requirement, can be used for manufacturing shells of electronic instruments and meters, can be used as a decoration material in a dust-free production workshop and can be used as shells and circuit boards of various flexible electronic products.