The invention relates to a method for computing an effective capacity coefficient of a large wind power base and a method for determining the capacity of a power transmission channel of the large wind power base. According to the method for computing the effective capacity coefficient of the large wind power base and the method for determining the capacity of the power transmission channel of the large wind power base, cost for receiving wind power is composed of three parts according to the wind power consumption process of a system, the three parts are wind power cost, power grid cost and peak shaving cost, the wind power cost comprises construction investment of wind power installation and operation and maintenance cost, the power grid cost comprises construction investment for delivering wind power out of a power grid, operation and maintenance cost and transmission loss cost, and the peak shaving cost comprises construction investment of a peaking power source, operation and maintenance cost and peak shaving loss cost; after the installed capacity of the wind power base is determined, the variation tendency of the wind power cost is contrary to the variation tendency of the power grid cost and the variation tendency of the peak shaving cost in the cost of per unit wind power along with the change of a selected capacity coefficient, the total cost which is the sum of the wind power cost, the power grid cost and the peak shaving cost of per unit wind power can reach a lowest point, the power transmission channel is established and a peaking power source is equipped according to a wind power capacity coefficient corresponding to the lowest point, the optimal economical point of wind power consumption of the whole system is achieved, and the wind power capacity coefficient corresponding to the lowest point is the power wind effective capacity coefficient.