The Wangzhai basin is a special recharge area for the Dawu water- rich district. It is characterized by complex geological conditions and study on its hydrogeological conditions is relatively poor. It is a simple and effective method to study hydrogeological conditions in this area by tracer test. The tracer test used Ammonium Molybdate as tracer lasted for 75 days. The duration curve of molybdenum ion concentration can be divided into single peak type, double peak type and multi- peak type. The average apparent velocity of groundwater is 233.73m/d. The experiment reveals that karst development of the Wangzhai basin is characterized by the coexistence of dissolution pore, dissolution gap, fissure, pipeline and karst cave, and channels for underground water contain single channel with or without tank and mutiple channels with or without tank. All the channesl are of mutiple directions and complexity. There are three main groundwater runoff channels, all of which lead to Zihe fault zone. The groundwater flows mainly to southwest, southeast and east (northeast) at a slower speed. Solutes migrate most rapidly to the east (northeast) direction. The Wangzhai fault and Bianhe fault have good water conductivity. Because the test was carried out in the dry season with less precipitation, and the daily periodic influence of groundwater exploitation was relatively stable, the groundwater flow field was relatively stable during the test period, and the test results reveal hydrogeological problems in a relatively accurate way.