The utility model relates to a disposable needle set. A floating sleeve, a needle, a compression spring and a trigger unit are arranged in an outer sleeve, wherein the needle embedded in the floating sleeve can be exposed after a shield of the floating sleeve is removed, two fixed ends of the compression spring are respectively fixedly connected with the outer sleeve and the floating sleeve, and the needle is concealed in the outer sleeve when the compression spring is not stressed. When using, the floating sleeve, together with the needle, is ejected to a perforated hole instantly via the compression spring after the trigger unit is pressed, and then the needle penetrates into a using portion oppositely. The floating sleeve and the needle are pulled back together when the compression spring recovers to an unstressed state, the needle is concealed in the outer sleeve, the compression spring is in a free unstressed stretching state, and then the floating sleeve and the needle can not be ejected again, thereby preventing others reusing the needle set with intent.