The invention discloses a high-strength, low-expansion and high-temperature alloy. The alloy is prepared from chemical components in percentage by mass as follows: more than or equal to 10% and less than or equal to 18% of Cr, more than or equal to 10.5% and less than or equal to 19% of Fe, more than or equal to 1.3% of Ti, more than or equal to 1.2% of Al, more than or equal to 3% of Mo, more than or equal to 0.2% and less than or equal to 4% of W, more than or equal to 0.1% and less than or equal to 0.8% of Si, more than or equal to 0.1% and less than or equal to 0.8% of Mn, more than or equal to 0.02% of C, more than or equal to 0.002% and less than or equal to 0.02% of B and the balance of Ni. According to the component design, the manner that gamma' phase precipitation strengthening and strengthening element solution strengthening are combined is adopted, and the relatively-high high-temperature strength is obtained; the alloy has the relatively low thermal expansion coefficient; and meanwhile, no precious metal cobalt is contained in the alloy, and the certain content of iron is added, so that the cost of the alloy is reduced, the machinability is improved, the cost performance of the alloy is greatly improved, and the alloy can be applied to components such as bolts, blades and the like for steam turbines for 650 DEG C-grade ultra-supercritical power stations.