The invention relates to the field of blow molding, in particular to a plastic bottle bottom cooler adjustable in height. The plastic bottle bottom cooler adjustable in height comprises a machine frame, a water tank, a water pump and water spraying structures. A lifting device is arranged at the lower ends of the water spraying structures and fixedly connects a nozzle body with a plastic bottle cooler. A sensor is arranged at the plastic bottle feeding end of a workbench, and a telescopic device used for adjusting the installation height of the sensor is arranged at the lower end of the sensor. According to the content, on the one hand, the lifting device of the plastic bottle bottom cooler adjustable in height enables the water spraying structures to be stably installed; on the other hand, the lifting device enables the water spraying structures to achieve lifting adjustment relative to the installation position; the telescopic device of the cooler enables the installation position of the sensor to be adjustable, and furthermore, the water spraying structures can adapt to cooling of more plastic bottles of different sizes.