The practical applications of solid-state inorganic CsPbX perovskite quantum dots (PQDs) have been restricted by their poor stability. Herein, we report an efficient large-scale synthesis of solid-state CsPbX PQDs across the full visible spectra using 3-Aminopropyltrimethoxysilane as ligands at room temperature in open air. The obtained green CsPbBr solids display outstanding optical performance with high color purity of 90% and photoluminescence quantum yield of 69.2%. Thanks to the protection of silica coating, the solid-state product shows much higher thermal stability, photo stability and long-term stability than that of naked CsPbBr QDs. The blue CsPb(Br/Cl) and yellow or red CsPb(Br/I) PQDs solids can be simply obtained via using alkali metal halide aqueous solution as additives. The white LED fabricated by combining the obtained green CsPbBr QDs solid powders and commercial red KSiF: Mn phosphor with a blue LED chip displays high luminous efficiency of 70.47 lm/W and the color gamut can cover over 129.4% of the National Television System Committee standard.