A convenient synthesis of $\alpha$-alkyl(or aryl) thio substituted vinyl phosphonates has been studied. Treatment or $\alpha$-sulfinyl phosphonates with trimethylsilyl triflate in the presence of hexamethyldisilazane and ethyl ether gives the corresponding vinyl phosphonates in good yields under the mild conditions. This reaction proceeds via Pummerer-type rearrangement of $\alpha$-sulfinyl phosphonates in the presence of weak base.