The invention relates to a 
polyester large-aperture 
conveyor belt and a preparation method thereof. According to the preparation method, high-strength 
polyester industrial yarns are obtained through 
solid phase polycondensation tackifying, melting, metering, extruding, cooling, oiling, stretching, 
heat setting and winding of the modified 
polyester, are then twisted and woven together to obtain a fabric layer, the fabric layer is coated with a synthetic 
polyurethane resin by two dipping and two rolling, and dried and baked to obtain the polyester large-aperture 
conveyor belt. An oiling agent used for oiling contains 
crown ether. The content of the 
crown ether is 67.30 to 85.58 wt%. The preparation method of the invention is simple and reasonable, and texture of the fabric layer of the polyester large-aperture 
conveyor belt finally obtained is a modified polyester with a molecular chain including a 
terephthalic acid chain segment, a glycol 
chain segment and a dihydric 
alcohol chain segment with g a branched chain, the 
breaking strength of the polyester large-aperture conveyor belt is equal to or more than 2900N, 
water pressure resistance is equal to or more than 100KPa, peel strengthis equal to or more than 9.0N / cm, when friction is equal to or more than 3500 times, 
coating does not change, and when temperature is equal to or less than -30 DEG C, the 
coating is crack-free.