The invention provides a Y-containing rear-earth permanent magnet alloy stripe-casting flake. A Y element is added in rare earth alloy Re-Fe-B, an alloy quick-setting and throwing technology is adopted, and a texture composed of a main phase columnar crystal and an intergranular phase is obtained, wherein Y mainly enters a main phase to form a crystal structure of 2:14:1, and a poor Y area is formed in a rare earth-rich phase. According to alloy stripe-casting flake, by regulating the Y content, distribution of the rare earth element in the main phase columnar crystal and the intergranular phase in the stripe-casting flake can be effectively adjusted, a foundation is laid for a rear-earth permanent magnet good in subsequent preparation performance, and the cost of preparing the magnet subsequently can be lowered.