Aiming at the insufficiency of color rendering of existing light-emitting diode (LED) based lamps used for indoor lighting, a solution of LED modules consisting of three different kinds of LED is proposed. Correlated color temperature (CCT), color rendering index (CRI) and luminous efficiency (LER) of LED modules are calculated when different numbers of three kinds of LED are set respectively. Influences of changing the number of each kind of LED on the results are analyzed. Besides, the selections of optimized combinations are described by setting results on CCT values of 3800 K and 4800 K as examples. Moreover, ideal results with high CRI (90 around) as well as good LER on different CCT values (3400 K~5600 K) are acquired. This solution is easier to impletment and more suitable for indoor lighting lamps compared with other methods used for improving CRI of white LED. This result may provide some guidance for the design of LED-based lamps with satisfying CRI for quality lighting.