The invention relates to a synthesis method of a vilazodone hydrochloride intermediate 5-(piperazino-1-yl)benzofuryl-2-formamide, belonging to the technical field of medicine synthesis. The synthesis method comprises the following steps: reacting a compound disclosed as Formula (I) with polyformaldehyde under reflux for 3-10 hours, carrying out cyclization reaction with ethyl chloroacetate at 80-120 DEG C for 3-24 hours, dissolving in alcohol, introducing ammonia gas, and reacting at 10-80 DEG C under the pressure of 0.1-2.0 Mpa for 3-24 hours to obtain a compound disclosed as Formula (IV), wherein the structural formulae of the Formula (I) and Formula (IV) are disclosed in the specification: when R is H, the compound disclosed as Formula (IV) is the product 5-(piperazino-1-yl)benzofuryl-2-formamide, and when R is a nitrogen protecting group, the protecting group can be removed to obtain the target product 5-(piperazino-1-yl)benzofuryl-2-formamide. The synthesis method has the advantages of low cost, short production procedure, high product yield and purity, and good product quality.