The multiobjective optimal dispatching of electric vehicles charging and discharging need take into account the benefits of both grid and users. Under the background, based on the improved membership function in vehicletogrid (V2G) mode, a multiobjective optimal scheduling model for electric vehicles charging and discharging is proposed, which aims to minimize the total load variance and the cost of the vehicle users. At the same time, the introduction of timeofuse price guides vehicle owners to orderly charge and discharge electric vehicles to reduce system load peaktovalley difference and promote the absorption of wind power. An improved membership function is proposed by using a reverse Sigmoid function to replace the traditional decreasing linear function, and the maximum fuzzy satisfaction method is utilized to convert the multiobjective optimization problem into a singleobjective problem. Then, the problem is solved by the Cuckoo Search algorithm. Finally, the impact of different timeofuse price, the number and average initial charge of participating vehicles on the optimization result is analyzed.