Due to the fast lateral changes of tight conglomerate reservoirs in Mahu area，difficult prediction of the interwell structures and reservoirs，and low drilling ratios of high-quality reservoirs，the geological modeling based on multiparameter constrained inversion was employed to characterize the three-dimensional spatial distribution of high-quality reservoirs，providing a solid basis for early warning and control of horizontal wells. The early-warning marker bed was established on the oil pay，and the local velocity field and structure as well as the geological model were updated according to the actual drilling data of the marker bed. The changes in key parameters，including target depth and horizontal-section dip angles，were forewarned. According to the prediction results of lithological rhythms along the well trajectory and the variation in resistivity while drilling，the early risk warning of drilling out of high-quality reservoirs in horizontal sections was carried out in time to improve the accuracy of target entry and drilling ratios of for high-quality reservoirs. When the positive rhythm area was drilled，the resistivity drop reflected the topcut，at a risk of top drill-out，which required early warning and a smaller hole angle；when the anti-rhythm area was drilled，the resistivity declined rapidly，at a risk of bottom drill-out，which demanded early warning and a larger hole angle. The application results in Mahu area demonstrate that the early warning technology by geological modeling based on multiparameter constrained inversion for horizontal wells enhances the drilling ratios of oil pays by 7.4% and cut the drilling period by 8.7%.