Under new situation, a large quantity of group events and resentment-venting evens happen frequently,and multivariate interests demands and political expressions appear time and then, which make the mass work befaced with lots new situations, problems and challenges. Physical field theory introduced, a deep and systematicstudy of the new situations, problems and challenges is conducted to analyze the display forms and basic featuresof mass work's field under new situation and a constructive idea is raised to construct the new systemand mechanism of mass work under new situation in this article.