Source and characteristics of coal big data were introduced, and present application situation of the coal big data was analyzed. Significance of platform development of the coal big data to its construction was expounded, and some problems existed in construction of the coal big data platform were analyzed about data sharing, data quality, safety, professionals and so on. It was pointed out that constructing the coal big data platform should make top-level design, improve standard system of coal data, train professionals and rationally design platform framework.