•Mn-doped CsPbCl3-SAM possess excellent optical properties.•Mn-doped CsPbCl3-SAM not only maintain the PQDs remarkable optical properties, but also improve their stability.•Mn-doped CsPbCl3-SAM can used as red phosphor and stacked on the.•Ce-PiG with InGaN blue chip to achieve warm WLED. Recently, more and more scholars synthesised the Mn-doped CsPbX3 (X = Cl, Br, I) inorganic perovskite quantum dots (PQDs), which exhibited a strong dopant luminescence characteristic of d-d transition of Mn2+ and dual-color emission. However, Mn-doped CsPbCl3 PQDs suffer from the instability, which hindered the application of PQDs in optoelectronic devices. Here, we resolve this problem with SiO2/Al2O3 monolith (SAM) through a simple sol-gel process and obtained a robust luminescent PQDs-SiO2/Al2O3 monolith (PQDs-SAM) with surprising high stability. This is an easy one-pot operation and can be done with large quantities. The composites not only maintain the PQDs remarkable optical properties, but also improve their stability, which is significantly. The Mn-doped CsPbCl3 PQDs-SAM in powder form is easily mixed into the resins and applied as color-converting layer with curing on blue light-emitting diodes (LED). And above all, the orange PQDs-SAM composite is used as red phosphor and stack on the Ce3+:YAG phosphor-in-glass (Ce-PiG) via screen-printing technology (Ce-PiG&R-PQDs-SAM). Whereafter, warm WLED is constructed by blending the Ce-PiG&R-PQDs-SAM materials with the InGaN blue chips. And the constructed WLEDs generate a warm white with an optimal luminous efficacy (LE) of 80.91 l m/W, a high CRI of 83.8, and a low CCT of 4082 K.