This study introduces an innovative method for reconstructing metamers, the aim is to identify metamerism when utilising white LEDs with high and low colour rendering. Two types of white LEDs were utilised as experimental light sources with two colour rendering indexes: high colour rendering (International Commission on Illumination (CIE) Ra of 95, TM-30 Rf of 92) and low colour rendering (CIE Ra of 78, TM-30 Rf of 78). Employ 741 training colours, principal component analysis was applied to extract basis function. Subsequently, 18 chromatic samples on ColorChecker colour chart were employed as target colours for spectrum reconstruction. Five sets of constraint were established to effectively filter potential metamers which are capable of inducing metamerism. Ultimately, three sets metamers were successfully reconstruct to differentiate white LEDs with high colour rendering, while an additional three sets of metamers were developed to distinguish white LEDs with low colour rendering. This outcome demonstrates the efficient method in reconstructing metamers to identify metamerism under high and low colour rendering white LEDs.