The invention discloses a method for preparing intermediate 3-methyl-2-butenol. The prior method has the defects of rigorous conversion reaction condition, low conversion rate, difficult separation, and high technical requirement. The method has the following steps of: putting 2-methyl-3-butene-2-hydrin and rearrangement catalyst into a reaction kettle, and heating the 2-methyl-3-butene-2-hydrin and rearrangement catalyst to undergo a catalytical rearrangement reaction to obtain the mixture of the 2-methyl-3-butene-2-hydrin and the 3-methyl-2-butenol; separating the mixture through a rectification tower, recovering the 2-methyl-3-butene-2-hydrin at the top of the rectification tower and returning the 2-methyl-3-butene-2-hydrin to the reaction kettle for feeding, obtaining the crude product of the 3-methyl-2-butenol through discharging from a lateral line of the rectification tower, and continuously replenishing new 2-methyl-3-butene-2-hydrin into the reaction kettle. The method has the advantages of no use of solvent, mild reaction condition and easy control, and realizes the continuous production based on the continuous feeding and discharging.