With the accelerated promotion of the lo w-altitude economy，low -altitude logistics is moving from the pilot exploration stage to normalized operation，which puts forward higher requirements for system -level digital support capability.This paper studied the digital infrastructure and digital twin system in low -altitude logistics and systematically combed the core composition and technical logic of its sensing and communication system，data fusion mechanism，modeling method，and scheduling optimization strategy.The study shows that the current digital system has a certain integration capability，but there are still structural barriers in data interface specification，platform synergy，and operation feedback mechanisms.The paper further points out that in the future，it is necessary to improve the scalability of the architecture，promote platform institutionalization，and enhance regulatory synergy to build a digital support base for city -level operation and provide theoretical support and technical paths for the large -scale application and intelligent scheduling of low -altitude logistics.