The invention discloses an active power quick regulation method for virtual small hydropower stations. The method comprises the steps of scanning and receiving the power and AGC regulation power of a real-time planning basic point in real time, and sending a received regulation instruction to each small hydropower station; detecting the active power of each tie line of a transmission section, setting up the distribution amounts by the active power regulation instruction received according to the sensitivity priority of each small hydropower station to the tie line when the transmission active power of any tie line approaches the stability limit; calculating the active power fluctuation quantity ratio of each tie line relative to the entire section, calculating the product of the ratio and the sensitivity of each small hydropower station to the tie line, summing the products of all the tie lines to obtain the index of the product of the section fluctuation quantity and sensitivity of each small hydropower station, and setting up the distribution priority of active power regulation instructions according to the values of the indexes. The method can quickly make a response, schedule and send active power regulation instructions, and can effectively restrain the transmission active power fluctuation caused by wind power.