Analyzing the theoretical connotation of harmonious consumption from the perspective of common wealth, this paper finds that harmonious consumption includes the harmony of consumption power, the harmony of consumption relations, and the organic unity of the two, in which the harmony of consumption power and the harmony of consumption relations respectively reflect the efficiency and fairness of common prosperity. In order to further clarify the development status of China’s harmonious consumption and its economic growth effect, according to the theoretical connotation of harmonious consumption, this paper exploratively constructs an index system of harmonious consumption power and harmonious consumption relationship, measures with the coupling coordination degree model the harmonious consumption level of 30 provinces in China from 2007 to 2020, and with the spatial econometric model, empirically examines the spatial effect of harmonious consumption on economic growth. The empirical results are as follows. First, from the perspective of time trend, China’s harmonious consumption level shows a fluctuating upward trend from 2007 to 2020, but on the whole, China’s consumption harmony needs to be further improved; from the perspective of spatial distribution, China’s harmonious consumption level presents an obvious spatial difference, which is “high in the east and low in the west, high in the coastal areas and low in the inland”. Second harmonious consumption has a significant positive spatial spillover effect on economic growth, and the conclusion is still valid after a series of robustness tests, such as eliminating outliers, increasing control variables and replacing spatial weight matrix. Third, further tests show that harmonious consumption can promote high-quality supply by optimizing the industrial structure and thus form a supply-demand linkage mechanism to promote economic growth. Therefore, it is suggested that the consumption power harmony should be promoted by increasing residents’ income and perfecting social security, the consumption relationship should be improved by narrowing the income gap and improving the social credit system, and demand-side management and supply-side reform should be synergistically promoted to facilitate high-quality economic development with a high level of dynamic equilibrium between supply and demand.