The invention discloses a lifting beam for a nuclear power steam turbine; the lifting beam can be used for lifting front and rear bearings of a low-pressure outer cylinder and includes a cross beam (1) and a plurality of counterweight blocks (2); a middle area of the cross beam (1) is provided with a first lifting point (11) for being lifted by a crane, and a first end of the cross beam (1) is provided with a second lifting point (12) for lifting a device; the counterweight blocks (2) are detachably assembled in a counterweight assembly area between a second end of the cross beam (1) and the first lifting point (11). The lifting beam has the advantages of simple structure and short size; single-point quick lifting is used, the maintenance efficiency is improved, the storage is convenient,and a detachable counterweight design is adopted, and the lifting work of bearing press plates, low-pressure front and rear bearings, low-pressure front and rear shaft seals and other devices with different weights can be satisfied by a scale type theory, operation is simple, and use safety is extremely improved.