The invention discloses a PET plastic flat filament drawing machine. The PET plastic flat filament drawing machine comprises a crystallization tower unit, a drying tower unit, a plastic extruding device, a thin film traction device and a filament cutting mechanism. The PET plastic flat filament drawing machine is characterized in that an automatic filter screen changing mechanism is arranged at the tail end of the extruding device, a flow-casting die head is arranged behind the automatic filter screen changing mechanism, and a high voltage electrostatic generator is arranged on the flow-casting die head; a filament strip traction mechanism is arranged behind the filament cutting mechanism, and then filament strips enter a flat filament traction device through a multi-roll heating system from the filament strip traction mechanism. PET materials, particularly crushed materials of waste mineral water bottles can be utilized for directing producing plastic flat filaments; filament fracture is not prone to occur in the production process, monofilament uniformity is good, and no sharp spine exists at all corners of a lateral bearing surface; the surface consistency of formed filaments is greatly improved, and solidity of a woven product is promoted; and the strength, the ultraviolet resistant capacity and aging resistance of the woven product can be improved in multiples, and contamination of plastic garbage to the environment is reduced.