Halide perovskite quantum dots (PQDs) have been intensively studied because of their superior optical properties and have great potential applications in laser, display technology and light-emitting diodes (LEDs). Presently, high-efficiency green emissive CH3NH3PbBr3 PQDs have been successfully fabricated. However, the synthesis of stable iodide-based CH3NH3PbX3 (MAPbX(3) (X = Cl, Br, I), MA = CH3NH3) QDs still faces significant challenges because they are sensitive to the moisture in open air. Herein, we investigated the effect of the solvent and ligand on the growth of the as-prepared MAPbBr(3) and MAPbI(3) sample, mainly involved in the volume ratio of N,N-dimethylformamide (DMF) and gamma-butyrolactone (GBL) and the amount of n-octylamine in toluene. The results show that the low volume ratio of DMF and GBL is beneficial to prepare highly luminescent, stable and full-colored MAPbX(3) PQDs in open air. Besides, the PL emission peak of MaPbBr(3) PQDs can be adjusted from 430 to 513 nm via precisely controlling the amount of n-octylamine in toluene because of quantization. The obtained MAPbX(3) PQDs show high quantum yield and a wide range of tunable light emission from ultraviolet to near-infrared region. The MAPbX(3) PQDs, especially iodide-based MAPbX(3) PQDs, obtained from this method remain stable more than 3 months at ambient condition. We further demonstrated the multi-colored LEDs by using different color emissive MAPbX(3) PQDs as color converters and being subjected to excitation through a blue GaN chip. Furthermore, MAPbX(3) PQDs are expected to show interesting nanoscale optical properties and have great potential applications in electroluminescence devices, lasers and optical sensors.