Equity financing is an important means for growth-type enterprises to capture growth opportunities and implement leap-forward development． However，whether to sign a valuation adjustment mechanism (VAM) in equity financing has long puzzled entrepreneurs． This paper studies VAM from the perspective of value creation and supply-demand matching． Based on the retailer’s risk aversion and ambiguity aversion decision-making behavior，the utility models with and without VAM are constructed，and the effects of VAM on retailer’s policy and utility are compared． The results show that there is a“VAM signing interval”，which helps to improve performance，even in the more conservative risk aversion case． In addition，the level of enterprise growth is the key factor for signing the VAM: entrepreneurs should sign the VAM when their enterprise has high growth opportunities; while if the growth opportunity is insufficient，the valuation and profit margin of the enterprise should be considered to determine whether to sign a VAM．