The invention discloses a shared car sharing site layout and selection model. The implementation process of the model includes the following steps of: establishing a shared rental car site selection cost model; establishing a network effect-based shared car rental profit model; establishing the objective function model of marginal costs and marginal profits; and using a firefly algorithm to simulate the objective function model. With the model adopted, problems in site layout with a strong network effect can be solved; and an improved firefly algorithm-based site selection model represented by sharing shared cars is built.