There has innate and initiative connection between trade union and welfare. The result of union contact with welfare is union welfare, that is, the welfare work of trade unions. The evolution of trade union welfare work in China went through four stages: fighting for welfare, undertaking nearly the whole welfare, distributing welfare and seeking welfare. The traditional welfare work of Chinese trade unions has historical and practical significance, but there are also many problems, which have different harm. In the future, the focus of trade union welfare work is "seeking welfare". In order to better benefit the staff, needing to achieve transformation from distributing welfare to seeking welfare in understanding, needing to figure out what kind of welfare to seek, for whom to seek welfare and how to seek welfare in practice.