The invention relates to an enricher for a mercury trap pipe and a mercury trapping device. The enricher comprises a body with an accommodating cavity, and a cover body buckled at the top end of the body, wherein a mercury trap pipe is placed in the accommodating cavity, and an air outlet communicated with the outside is formed in the lower end of the body; the cover body is provided with an air inlet communicated with the outside. According to the enricher, pollution of substances attached to the outer side of the mercury trap pipe to gaseous mercury can be reduced when the gaseous mercury is reclaimed from the mercury trap pipe, and the accuracy in data analysis can be effectively improved. The enricher is simple in structure, low in cost and convenient in use, and is convenient for collecting gaseous mercury outdoors, preserving and transporting.