Green combined preparation method of rare earth fluoride

A green combined preparation method of rare earth fluoride comprises the steps that raw materials are prepared according to a preset proportion, and the raw materials comprise rare earth oxide and hydrogen fluoride gas; carrying out reaction on the rare earth oxide and hydrogen fluoride gas by adopting a dry fluorination process to generate rare earth fluoride; excessive hydrogen fluoride gas is recovered and converted into liquid hydrofluoric acid; the method comprises the following steps: reacting recovered liquid hydrofluoric acid with rare earth carbonate by adopting a wet fluorination process to obtain a precipitate of rare earth fluoride; according to the method, on the basis of a dry fluorination process, a falling film absorption tower tail gas treatment device is introduced, and excess hydrogen fluoride gas generated by the dry fluorination process is collected and converted into liquid hydrofluoric acid. And introducing a wet fluorination process to convert the liquid hydrofluoric acid into rare ear