The invention discloses a method for preparing uniform nano-microspherical Na0.5Bi0.5TiO3 crystals. According to the method, metal salt serves as a raw material and is mixed with an organic solvent, and a mixed solution is prepared; an alkaline aqueous solution is added, oxyhydroxide precipitates of titanium and bismuth are prepared and serve as reactants, a proper quantity of sodium hydroxide water solutions is added, slurry is obtained, an Na source is provided, crystalization is promoted, the slurry is kept at the temperature of 175-185 DEG C for 23-25 h, sodium bismuth titanate nanoscale uniform microspheres are obtained after a hydrothermal reaction, and the diameter of microspheres in a typical characteristic scale is about 100-150 nm. With the adoption of the method, sodium bismuth titanate nano-microspheres are synthesized, the microspheres are in perfect spherical distribution and have extremely high uniformity, the radius of the microsphers is easy to control, and the process is convenient to implement, has no rigid requirements for experimental equipment, is low in cost, causes little pollution and facilitates large-scale production. The product can be used for preparation of high-performance piezoelectric ferroelectric ceramics and has infinite prospects in fields such as detectors, transducers, electro-optic devices, photovoltaic devices, electromechanical coupling devices and the like.