We developed a synthesis method for silica‐coated quantum dot (QD)‐densely‐embedded silica nanoparticle (Si@D‐QD@Si NP) with remarkably brighter fluorescence by increasing the number of QDs on silica NPs. Si@D‐QD@Si NPs exhibited a narrow size distribution and a high signal reproducibility. Red, green, and blue Si@D‐QD@Si NPs were successfully fabricated and characterized. The Si@D‐QD@Si NP carried 2.4 times more QDs than previously reported silica‐coated QD‐embedded silica NP (Si@QD@Si NP). The quantum yield of Si@D‐QD@Si NPs was slightly higher than Si@QD@Si NPs. The red Si@D‐QD@Si NPs showed approximately 26.6%, the green Si@D‐QD@Si NP 36.2%, and the blue Si@D‐QD@Si NP 39.3% higher fluorescence intensity compared to the corresponding Si@QD@Si NPs. This result implied that the particles can be used at bio‐field with a higher sensitive detection.