Disclosed are a type of conjugated triene compounds (1), and a preparation and application thereof. In this method, a 2-(cyclohexenylidene)malonic acid derivative is sequentially subjected to isomerization, halogenation reaction in the presence of a halogenating agent and dehydrohalogenation to prepare the conjugated triene compounds (1). This disclosure further provides a method of preparing a 2-aryl malonic acid derivative from the conjugated triene compounds (1) through aromatization reaction.