1,4,6,10-tetra-double bond pentadec-carbon phosphonate of formula (4), and preparation method thereof are provided. The preparation method comprises: reacting a pseudo ionone of formula (2) with sulfonium salt to prepare a epoxide of formula (9), and then reacting the epoxide of formula (9) with magnesium bromide to prepare a C-14 aldehyde of formula (3); condensing the C-14 aldehyde of formula (3) with tetra-alkyl methylene diphosphonate to obtain 1,4,6,10-tetra-double bond pentadec-carbon phosphonate of formula (4). Furthermore, the preparation method of lycopene via 1,4,6,10-tetra-double bond pentadec-carbon phosphonate of formula (4) is also provided. The present method has the advantages of short route, easily obtained raw materials, and low cost.