To investigate effective methods for mitigating divertor heat loads on the J-TEXT tokamak, compact magnetic geometries with the X-point in close proximity to the target were realized by adjusting the divertor coil current. Subsequently, the compact radiative divertor (CRD) configuration was established through CH4 injection from the private flux region. Specifically, the primary X-point divertor (PXD) is identified as an extreme case of the CRD, where the distance between the X-point and the divertor target is extremely close to zero. Experimental results indicate that the compact configurations achieve a lower detachment density threshold and reduced target heat flux compared to the conventional single-null configuration. Notably, the extreme PXD regime demonstrates the most favorable performance. During detachment, the CIII radiation peak migrates inward across the last closed flux surface from the X-point and shifts poloidally upward from the X-point. SOLPS-ITER simulations of the CRD configuration reproduced the lower detachment threshold and the experimentally observed C III radiation evolution. These findings demonstrate that the compact magnetic geometries may provide a viable approach for lowering the target heat load and facilitating detachment at lower density thresholds in tokamaks. Furthermore, both experimental measurements and numerical simulations show that the detachment density threshold increases with higher electron cyclotron resonance heating power, indicating that high-power auxiliary heating in future reactors may raise the operational density requirement for detachment.