The purpose of the present invention is to provide a preparation method which enables the easy and efficient (high yield, high selectivity, low cost) preparation of fluorine-containing olefins having organic-group substituents, from fluorine-containing olefins. A preparation method for fluorine-containing olefins having organic-group substituents, said method being characterised by including a process in which fluorine-containing olefins are reacted with an organic boron compound in the presence of an organic transition metal catalyst which contains a transition metal selected from nickel, palladium, platinum, rhodium, ruthenium, and cobalt.