Abstract:Applicaion of highprecision magnetic survey in investigation and assessment of iron ore in Longwanmiao area in Shanxian county has been described in this paper. Application of highprecision magnetic survey aims to break down magnetic surveying anomaly with the scale of 1 ∶50000 in early period, reflect distribution of magnetic anomalies in Longwangmiao area in detail, and provide basic information for investigation and evaluation of iron ore predication in this area. Based on highprecision magnetic survey work in recent years, ore exploration in deep part of iron deposit in this area has achieved a major breakthrough. Liujiazhuang sedimentarymetamorphic iron deposit with large scale has been found, oreforming valuable predication has been carried out, and has gained a good geological effects.