The southern North China Basin is located in the transition zone between the Qinling-Dabie orogenic belt and the North China Plate. Karst thermal reservoirs of the Lower Paleozoic Cambrian-Ordovician are well-developed in this area, yet a systematic evaluation of the Lower Paleozoic geothermal resources has not been conducted previously. By integrating drilling and geological data of the Lower Paleozoic, the karst geothermal potential of the Lower Paleozoic in the southern North China Basin was systematically evaluated for the first time, and the favorable areas and resource potential of geothermal resources were pointed out. The results show as follows. The southern North China Basin is generally characterized by medium-low temperature geothermal resources, with the geothermal gradient ranging from 1.96 ℃/100 m to 2.9 ℃/100 m (with an average of 2.69 ℃/100 m). On the plane, it presents the characteristics of being higher in the north and east and lower in the south and west. The Kaifeng Depression has the highest geothermal temperature (100~200 ℃), while most areas of the Taikang Uplift and Zhoukou Sag have temperatures of 100~150 ℃, with some local abnormal high-temperature points. The thickness of the Ordovician thermal reservoir is 40~100 m with a porosity of 4%~7%; the Cambrian is thinner than the Ordovician (mostly < 15 m) and has a lower porosity (generally < 3%). The Taikang Uplift is optimized as the favorable area for the Lower Paleozoic thermal reservoirs, and the estimated Lower Paleozoic geothermal resource amount is 55 623.78×10¹⁷ J, of which the Ordovician accounts for 82%. Based on a comprehensive analysis of tectonic conditions, reservoir properties and geothermal temperature, the western (Zhengzhou-Weishi County) and eastern (Fugou County-Taikang County-Zhecheng County) parts of the Taikang Uplift are delineated as the core favorable areas for geothermal development, and the central part (Weishi County-Tongxu County-Qixian County) is defined as the relatively favorable area.