The invention relates to a high-flow and temperature-resisting PPO/PA composition for LEDs and a preparation method thereof. The PPO/PA composition comprises the following components by mass percent: 20-50 percent of polyphenyl ether, 20-50 percent of polyamide, 2-8 percent of a compatilizer, 5-15 percent of a fire retardant, 2-15 percent of polyolefin, 10-25 percent of titanium dioxide, 2-10 percent of a flexibilizer, 1-4 percent of a dispersant, and 0.2-0.6 percent of an antioxygen; the preparation method comprises the following steps: drying titanium dioxide, adding the dispersant, polyphenyl ether, polyamide, compatilizer, flexibilizer and antioxygen, and adding the components from a main feed opening of a twin-screw extruder; after the fire retardant and polyolefin are mixed according to a ratio, adding the mixture by a feed pump from a fourth-section cylinder of the twin-screw extruder; extruding and pelleting, so that the composition is prepared. The high-flow and temperature-resisting PPO/PA composition for LEDs has superior heat resistance, superhigh shading performance and excellent flowability, as well as favorable fire resistance and size stability, meets the requirement of ROHS and Reach regulations, and facilitates the realization of the production of products such as LED nixie tubes with the thickness of 0.2 mm and lattice modules.