Three ways are used to study the pricing ways of risky investment projects, namely discounting way of the end value, discounting way of cash flow and option pricing way. An example is given to study the practical use of the three ways which have different characteristics and constrained conditions. Compared with each other, it is found that option pricing way has a distinguished advantage, since this way involves the effect of the uncertainty of the value of enterprises on the value of equity, and solves the problem of the low valuation of the value of enterprises caused by the fact that the return of the first years is less than the return of the later years. At the same time, the effect of the change of capital structure on the value of equity is taken into account. Anyway, in some sides the three ways have the similar difficulties.