Luminescent nanofluids are successfully prepared by directly dispersing organometal halide perovskite nanocrystals (OHP NCs) with different emission colors in silicone oils. The photoluminescence quantum yields of nanofluids with green, blue and red emission are 47, 32, and 19%, respectively. Furthermore, the nanofluids greatly enhance the stability of OHP NCs and show excellent resistance against moisture, heat and ultraviolet light. The luminescent nanofluids can be used as liquid color converter for LED. By loading them onto silica aerogel, luminescent perovskite powders were achieved. Their applications as phosphor additives for preparing luminescent PMMA composites were demonstrated.