By using the survey data of Chinese urban household consumption finance, this paper systematically analyzes the influence of improved financial knowledge index, economics major, finance major, and related financial planning on family wealth accumulation, and verifies that the significant positive impact of financial knowledge on household wealth accumulation is robust. In addition, the positive marginal effect of family financial planning and the time span of financial planning indicates that financial planning may be an important mechanism of financial knowledge differences affecting family wealth accumulation. The conclusion is helpful to further understand the impact of financial knowledge differences on family welfare, especially retirement welfare.