The invention relates to (E)-3-(2,4,5-trimethoxy-phenyl)-prop-2-en-1-ol, and a preparation method and application thereof. Related (E)-3-(2,4,5-trimethoxy-phenyl)-prop-2-en-1-ol has the structural formula I shown in the specification. The related preparation method comprises: performing decarboxylation reaction on 2,4,5-trimethoxybenzaldehyde, isopropylidene malonate (meldrum's acid) and a fatty alcohol under catalytic effect of pyridine and piperidine, so as to obtain (E)-2,4,5-trimethoxycinnamate, and processing by using a reducing agent, so as to obtain (E)-3-(2,4,5-trimethoxy-phenyl)-prop-2-en-1-ol. The preparation method is simple and relatively high in yield. The related application comprises that (E)-3-(2,4,5-trimethoxy-phenyl)-prop-2-en-1-ol is applied to prepare medicines for calming, tranquilizing, resisting senile dementia, resisting convulsion, resisting epilepsy or protecting heart and cerebral vessels.