The present application relates to a synthesis method for cariprazine, comprising performing an acylation reaction between a compound represented by formula (I) and dimethylcarbamoyl chloride in a reaction solvent in the presence of an aqueous solution of an inorganic base, so as to obtain the cariprazine compound represented by formula (II). The synthesis method overcomes defects in the prior art such as a long reaction time, large size impurities and the difficulty of purification, and provides a new method suitable for commercial production wherein the reaction is fast, impurity sizes are small, the product is easily purified, the purity of the product can reach 99.0% or more, and the yield is high.