Abstract: With the increase of renewable energy integration and the scale of the DC feed-in receiving-end power grid, the frequency safety constraint faults change from permanent power impact faults such as DC blocking to short-term power impact faults such as short-circuit faults, and the frequency characteristics and the countermeasure adaptability are unclear. In this paper,the meaning of key factors is sorted out based on the frequency dynamic response process, and the changes in the characteristics of key factors under short-term power impact are analyzed considering the dynamic response processes such as renewable energy and DC. Combined with the influence of key factors on frequency characteristics, the frequency characteristics under short-time power impact are studied from four aspects, i.e., the maximum frequency change rate, maximum frequency deviation and arrival time,quasi-steady state frequency deviation, and frequency spatio-temporal distribution. Finally, the countermeasures to the frequency problem under short-time power impact in receiving-end power grid are discussed.