Western social media is an international communication platform which has power to affect the cognition and value judgment of foreign audiences deeply.Xinhua news agency，as the official press agency of China，has carried out publicity work on Twitter，Facebook and YouTube etc.while it has achieved good communication effects these days.This research makes a comprehensive analysis on the reporting and operation of Xinhua news agency in western social media platforms by big data quantitative analysis tools while it may provide valuable references for the practice of China's international communication.