The invention provides a purification separation device for fogdrop and granules in gases. The purification separation device comprises a front-end separator, wherein the front-end separator comprises an outer-layer shell (6) and an inner-layer shell (9); an annular cavity is formed between the outer-layer shell (6) and the inner-layer shell (9); one end of the inner-layer shell (9) is a gas inlet end (1); the other end of the inner-layer shell (9) is a gas outlet end (12); a centrifuging part (2) for converting fed straight airflow into rotational airflow is arranged at the gas inlet end (1) of the inner-layer shell (9); between the centrifuging part (2) and the gas outlet end of the inner-layer shell (9), a plurality of exhaust holes (3) which are communicated with the annular cavity and interior of the inner-layer shell (9) are formed in the side wall of the inner-layer shell (9). By adopting the purification separation device for fogdrop and granules in gases, captured fogdrop and granules can be conveniently and rapidly discharged out, and thus a relatively remarkable separation effect is achieved.