Segmental fracturing technology is widely used in horizontal well production, but it is difficult to accurately measure the production contribution of each segment after fracturing and to accurately depict the fracture structure, so this paper investigates the production contribution and fracture connectivity by tracer technology. In this paper, the X12 well of the Jing-he oil field in the southern Ordos Basin is selected as a fracturing tracer injection well for research and analysis. Nine different types of oil and water sample tracers were injected into nine fractured sections, and the contribution of fluid and oil production in each section was obtained by analyzing 1332 samples obtained from actual production monitoring. The study shows that among the fractured sections with production monitoring, four sections with production contribution greater than 15% show fracture response on logging curves, and two sections with production contribution less than 15% have 5% and 2% respectively, and the logging data show poor physical properties and no fracture response. Therefore, the X12 well is located in the fault and fracture with higher production contribution and in the matrix section with lower production contribution. In addition, the tracer results showed the same as the micro-seismic results when fracture connectivity was studied. This provides a new idea and method for evaluating the fracturing capacity and fracture connectivity of horizontal wells in the future.