The utility model discloses a medicament liquid preparation device for preparing oxytocin. The utility model belongs to the technical field of liquid preparation devices. The liquid preparation tank comprises a liquid preparation tank body, a stirring mechanism is arranged at the upper end of the liquid preparation tank body; a feeding hole is formed in one side of the stirring mechanism; a thermometer is arranged on the other side of the stirring mechanism; the filter screen cylinder provided by the utility model is simple to install; when the filter screen cylinder needs to be cleaned or replaced; rotatably opening a fixed sleeve, the filter screen cylinder is drawn out by the drawing pull ring; cleaning of filters, re-installation, the fixed cylinder seat is pressed against the shell ofthe discharging mechanism; the end opening of the ring seat is covered by the cylinder cover; the liquid preparation tank is simple to mount and demount and convenient to replace, the liquid preparation tank body can be directly cleaned by the aid of the corrugated spray head without additional equipment, the corrugated spray head is cleaned by the aid of a spherical surface cleaning technology with 360-degree spherical surface space, cleaning is thorough, time is saved, and production efficiency is improved.