Big data age is coming. What changes will happen to government governance under the driven of big data? There are few studies. The current test of government governance focuses on the prevention of poverty return in the field of targeted poverty alleviation. Based on this perspective, this paper explores the internal mechanism of government governance driven by big data. The study finds that: under the background of big data, the government's governance ability has spawned new core competence, namely data management ability. Diversification of government governance subjects is beneficial to realize the wide range and precision mobilization of government governance resources. The change from empirical decision-making to data decision-making is beneficial to realize the high efficiency and fair allocation of government resources. The precise identification of object of government governance is conducive to the accurate and optimal use of government resources. Objectively, we must have the ability of data governance. Subjectively, we must reconstruct the government governance system (including governance subject, governance mode and governance object) according to the requirements of big data driving. Only in this way can we truly realize the purpose of data governance driving government governance and improve the government governance ability. Objectively, data management ability can accelerate the reconstruction of the government governance system, then accelerate the improvement of government governance capacity and finally improve governance performance. Based on the analysis of the deficiencies and gaps between conventional and big data prevention of poverty return according to the different stages of big data application, some targeted suggestions such as reconstruction of government governance system and improvement of data governance capability are put forward.