A method for crystallization of β-ammonium tetramolybdate includes: performing a stepwise pH-adjusting treatment of an ammonium molybdate solution via zoning to obtain the β-ammonium tetramolybdate. When feeding the ammonium molybdate solution into a reaction system from a first zone and then into second to sixth zones successively, pH1 of a resultant solution in the first zone is 7.0-6.0; pH2 of a resultant solution in the second zone is less than 6 and greater than or equal to 4; pH3 of a resultant solution in the third zone is less than 4 and greater than or equal to 2.5; pH4 of a crystallized slurry in the fourth zone is less than 2.5 and greater than or equal to 1; pH5 of a crystallized slurry in the fifth zone is 2.5-4.0; and pH6 of a crystallized slurry in the sixth zone is less than 2.5 and greater than or equal to 2.0.