The invention relates to a sensitive material SnS-SnO2 for Hg(0) sensors, and belongs to the technical field of semiconductor sensors. A purpose of the present invention is to provide a sensitive material SnS-SnO2 used for Hg(0) sensors and used for SnS-SnO2 resistance type sensors, wherein the SnS-SnO2 resistance type sensor is used for detecting Hg(0) and is based on a sulfide semiconductor as atemplate. The preparation method comprises: weighing stannous chloride, and dissolving in deionized water under stirring; separately, sequentially and completely dissolving sodium hydroxide, thiourea, ammonium fluoride and P123 in deionized state under stirring; stirring for 10 min after completely dissolving, transferring into a reaction kettle, carrying out hydrothermal treatment at a temperature of 160 DEG C, and maintaining for 12 h; naturally cooling the reaction kettle under high pressure to achieve a room temperature, and respectively washing the black product three times with deionized water and ethanol; and collecting the washed black product, and drying for 24 h in a vacuum oven, wherein the temperature of the vacuum oven is set to 60 DEG C. According to the present invention, the sensitive material SnS-SnO2 has good gas sensitivity to Hg(0), and finally can detect the content of Hg(0).