Blockchain technology can effectively alleviate consumers' doubts about green products caused by online sales, and different sales models will affect manufacturers' blockchain application decisions. Based on this, four kinds of e-commerce supply chain decision-making models are constructed when the manufacturer adopts or doesn't adopt blockchain under the reselling and agency modes, and the sales modes selection and blockchain application strategies of the manufacturer, as well as the impact of blockchain applications on environment and social welfare, are analyzed considering consumer questioning. It shows that the enhancement of e-commerce platform's ability to expand the market and consumers' environmental awareness are conducive to mitigating the negative impact caused by the increase of consumers' questioning and blockchain application costs. The manufacturer and e-commerce platform only jointly prefer the agency mode when the commission rate is moderate. Moreover, the increase of consumer questioning and blockchain application costs will reduce the likelihood of both parties jointly favoring the agency mode. Only when the blockchain applications cost is less than a certain threshold or the consumer questioning level is greater than a certain threshold, the manufacturer and e-commerce platform can also benefit from blockchain applications, and the threshold range for both parties to benefit under the reselling mode is always larger. Even if the manufacturer applies blockchain can improve the green design level of products and its profit, it may not necessarily have the effect of weakening the overall environmental impact of products and increasing social welfare.