Disclosed are 5 bromine 2 (a hydroxypentyl)benzoic acid sodium salts in different crystal forms and a preparation method thereof relating to the field of medicinal chemistry. The 5 bromine 2 (a hydroxypentyl)benzoic acid sodium salts in different crystal forms comprise: an amorphous 5 bromine 2 (a hydroxypentyl)benzoic acid sodium salt a 5 bromine 2 (a hydroxypentyl)benzoic acid sodium salt in crystal form A and a 5 bromine 2 (a hydroxypentyl)benzoic acid sodium salt in crystal form B. The different forms of 5 bromine 2 (a hydroxypentyl)benzoic acid sodium salts obtained in the present invention have better stability and water solubility than mixed 5 bromine 2 (a hydroxypentyl)benzoic acid sodium salts which is conducive to drug use. Meanwhile the therapeutic effect of the 5 bromine 2 (a hydroxypentyl)benzoic acid sodium salts in different crystal forms are obviously better than that of the 5 bromine 2 (a hydroxypentyl) potassium benzoate.
