依据痕量Ｈｇ（Ⅱ）对Ｆｅ（ＣＮ）_６~（４－）－α，α＇－联吡啶配体交换反应的催化作用，建立了快速测定痕量Ｈｇ（Ⅱ）的停流流动注射分析法，引入硫脲作活化剂可显著提高测定的灵敏度。线性范围为０～７５ｎｇ／ｍＬ，方法检测限为０．５ｎｇ／ｍＬ。Ａｇ（Ⅰ）严重干扰测定，Ｆｅ（Ⅲ）、ＣＯ（Ⅱ）以及Ｚｎ（Ⅱ）对测定有轻度干扰，其余大部分常见共存离子不影响测定。用本法测定了水中的汞含量，结果满意。 Based on the catalytic effect of trace Hg(II) on the exchange reaction of Fe(CN)_6~(4-)-α,α’-dipyridyl ligands, established flow-injection analysis for the rapid determination of trace Hg(II). The introduction of thiourea as an activator can significantly increase the sensitivity of the assay. The linear range is 0-75 ng/mL and the method detection limit is 0.5 ng/mL. The Ag (I) was heavily interfered with the measurement. Fe (III), CO (II), and Zn (II) slightly interfered with the assay. Most of the other common coexisting ions did not affect the assay. The mercury content in water was measured by this method and the results were satisfactory.