X‐ray imaging has received sustained attention for healthcare diagnostics and nondestructive inspection. To develop photonic materials with tunable photophysical properties in principle accelerates radiation detection technologies. Here the rational design and synthesis of doped halide perovskite CsCdCl3:Mn2+, R4+ (R = Ti, Zr, Hf, and Sn) are reported as next generation X‐ray storage phosphors, and the capability is greatly improved by trap management via Mn2+ site occupation manipulation and heterovalent substitution. Specially, CsCdCl3:Mn2+, Zr4+ displays zero‐thermal‐quenching (TQ) radioluminescence and anti‐TQ X‐ray‐activated persistent luminescence even up to 448 K, further revealing the charge‐carrier compensation and redeployment mechanisms. X‐ray imaging with the resolution of 12.5 lp mm−1 is demonstrated, and convenient 3D X‐ray imaging for the curved objects is realized in a time‐lapse manner. This work demonstrates efficient modulation of energy traps to achieve high storage capacities and promote future research into flexible X‐ray detectors.