The invention relates to the field of precipitation-strengthened austenite alloys, in particular to a Fe-Ni base precipitation-enhanced austenite alloy and a preparation method. The austenite alloy comprises the following elements in percentage by mass: 27 to 32 percent of nickel, 13 to 17 percent of chromium, 0.5 to 2 percent of molybdenum, 1.5 to 3 percent of titanium, 0.1 to 0.5 percent of aluminum, 0.1 to 0.6 percent of vanadium, 0.1 to 0.6 percent of silicon, 0.0005 to 0.02 percent of boron, less than 0.02 percent of carbon and the balance of iron and inevitable impurities. In the invention, the Fe-Ni alloy is taken as base, the content of the element boron in the alloy is improved, appropriate hot machining, and thermal treatment and hot hydrogen filling processes are performed, so that the crystal boundary precipitated phase of the alloy is controlled under a reasonable thermal treatment rule, and high mechanical property and high hydrogen damage resistance of a prepared alloy material are ensured. The precipitation-enhanced austenite alloy can be applied to hydrogen close environments of industries with high requirements such as aviation, nuclear energy, petrochemical industry and the like.