Abstract: Investment decision about grid-connected renewable energy is not only affected by technology, cost, policy and other uncertain factors, but also greatly influenced by the competitive relation between same and different electric technologies of renewable energy. For two kinds of different electric technologies of renewable energy, the mode of option game in choosing the investment timing shall be constructed and the features of investment decision about grid-connected renewable energy shall be analyzed. The results show that the discrimination of power grid on the acquisition of two kinds of renewable electric power will decide the equilibrium types of duopoly companies of renewable energy in the game of choosing the investment timing. With certain parameters, the discrimination of the acquisition of power grid grows from small to big while the equilibrium types produced in the game are correspondingly the simultaneous investment equilibrium, the preemption equilibrium, and the sequential investment equilibrium.