Perovskite light-emitting diodes are promising next-generation optoelectronic devices owing to their exceptional characteristics. Due to these reasons, intensive research has been conducted over the decade. However, the development of deep-blue PeLEDs, crucial for meeting Rec.2020 standards, lags behind those of red and green counterparts. In this study, we present a simple solid-state halide exchange method to incorporate chloride moiety into perovskite emission layers. This method enables a facile tuning of the emission spectrum from the green region (510 nm) to the deep-blue region (434 nm). Notably, we achieved a PLQY of 48.9% at 462 nm with a full width at half maximum (FWHM) of 21 nm. Furthermore, the PeLEDs fabricated by this method exhibited an EQE of 1.6% and a luminance of 1146 cd/m² in the deep-blue region (471 nm) with narrow FWHM of 19 nm, maintaining excellent color stability. Our results provide a facile way for fabricate highly bright, efficient deep-blue PeLEDs.