The present invention provides a coagulation bath apparatus for dry-jet wet-spinning para-aramid and a spinning method therefor, relating to the technical fields of spinning apparatuses and processes. In the present invention, a coagulation bath plate (1) is internally provided with a spinning tube (107) for spinning, an accelerating device (2) is sleeved on the spinning tube (107), and triangular gaskets (7) are mounted between the accelerating device (2) and the spinning tube (107); screw holes (113) and guide grooves (114) are provided on a plate support (112) of the coagulation bath plate (1), and screw rods (3) are in threaded fit connection with the screw holes (113); and the accelerating device (2) is fixedly mounted at the guide grooves (114) by means of bolts (4), washers (6), and nuts (5). Compared with the prior art, the height of the coagulation bath in the present invention is easy to change so as to adjust the height of an air layer; the accelerating device is provided to conveniently adjust the flow rate of the coagulation bath and the position of the accelerating device is adjustable, balancing the speed difference between the flow rate of the coagulation bath and the spinning speed. Said apparatus has a simple structure and allows convenient position adjustment, and can adapt to a spinning method with a spinning speed of 200-600 m/min.