In the era of“Internet +”，crowdfunding has gradually become a new mode of e-commerce. After analyzing the features of the crowdfunding pattern，this paper proposed a value measurement model of network externality in a crowdfunding platform by choosing the characteristics of network externality and the structure of perfect monopoly market as the breakthrough points. The established model contains two functions: the crowdfunding initiator’s revenue function and the consumer utility function，with the latter considering both the macro and the micro network externality. By solving a two-stage game model，the optimal price vector of the crowdfunding initiator，the optimal subscribing amounts of investors and the optimal income level of the crowdfunding initiator are derived in the three cases of differential pricing strategy，single uniform price strategy and the benchmark without network externality，respectively. Besides，the strategic value and intrinsic value of network externality are obtained by comparing the optimal revenues of the crowdfunding initiator under different strategies，which is the foundation of designing profitable referral networks in a crowdfunding platform with the function of recommendation. These results show that the proposed crowdfunding platform with the recommendation function enables to encourage the market participants to recommend more people to join in the crowdfunding project so as to greatly raise the crowdfunding initiator’s income level. To sum up，the proposed model is meaningful for the crowdfunding initiators to raise their income levels and further for the market participants to improving the marketing modes in a crowdfunding platform.