The present invention relates to the field of plasma chemistry, and discloses a low temperature plasma reaction apparatus and a method for decomposing hydrogen sulfide. The low temperature plasma reaction apparatus comprises: an inner cylinder (1); an outer cylinder (2) nested in the outer portion of the inner cylinder (1); a center electrode (3) arranged in the inner cylinder (1); a grounding electrode (4) arranged around the side wall of the inner cylinder (1); and a barrier medium (6) arranged on at least part of the outer surface of the center electrode (3), wherein a ratio (L1:L2) of thedistance L1 between the outer side wall of the barrier medium and the inner side wall of the grounding electrode to the length L2 of a discharge region is 1:(0.5-6000). According to the present invention, the low temperature plasma reaction apparatus can achieve the continuous and stable performing of the hydrogen sulfide decomposition process at a significantly high hydrogen sulfide conversion rate, and can achieve long-cycle operation.