The invention discloses a method for preparing 
lithium salt ore from 
plateau sulfate type 
salt lake brine. The method comprises the following steps of: evaporating 
sulfate type 
salt lake brine to be in the 
sodium chloride saturated state, freezing in winter to separate out 
mirabilite, and carrying out 
solid-liquid separation when the content of the 
sulfate ion in the brine is controlled to be 1g / L to 7g / L; evaporating the brine from which the 
mirabilite is separated out, so as to separate 
sodium chloride; evaporating the brine from which the 
sodium chloride is separated out, so as to separate out sylvine, 
carnallite and epsomite, carrying out 
solid-liquid separation when the 
lithium ion concentration in the brine is controlled to be greater than or equal to 6g / L, wherein the brine subjected to 
solid-liquid separation is the brine with 
high magnesium chloride content; mixing the brine with 
high magnesium chloride content with the 
mirabilite to react so as to separate out 
sodium salt and 
magnesium salt, and carrying out solid-liquid separation when the 
magnesium-
lithium ratio in the solution is controlled to be less than or equal to 8:1, so as to obtain 
boron-lithium-rich brine; and reacting the 
boron-lithium-rich brine with water to separate out 
boron rock, carrying out solid-liquid separation so as to obtain lithium-rich brine; and introducing the lithium-rich brine into a lithium salt 
pool, and evaporating so as to separate out the lithium salt ore.