本文报道了用氢氧化镁共沉—火焰原子吸收分光光度法测定水中镉、铅、锌、铜、铁、锰的实验方法。6种元素的捕集率为91～100％,方法的相对标准偏差为0.52～4.3％,回收率在90～105％,浓缩10倍。用虹吸法可以容易地把母液和沉淀分开,免去了繁琐的过滤或离心操作,具有简便、快速、无毒、无害、捕集效率高等优点。 This paper reports the experimental method for the determination of cadmium, lead, zinc, copper, iron and manganese in water by magnesium hydroxide co-precipitation-flame atomic absorption spectrophotometry. The collection rate of the six elements was 91-100%. The relative standard deviation of the method was 0.52-4.3%, the recovery was 90-105% and the concentration was 10 times. Siphon method can be easily separated with the mother liquor and sedimentation, eliminating the cumbersome filtering or centrifugation, with the advantages of simple, fast, non-toxic, harmless, high capture efficiency.