In recent years, with the rapid increase in the penetration rate of new energy sources and the scale of direct current (DC) injection, the inertia level of the receiving-end power grid has been continuously decreasing, leading to an increasingly prominent frequency security issue. Under different types of disturbances such as DC blocking and commutation failure, the receiving-end power grid is at a high risk of frequency collapse, necessitating a clear understanding of its minimum inertia requirements. To address this, this paper proposes an assessment method for the minimum inertia requirements of the receiving-end power grid considering different types of faults. Firstly, a multi-machine frequency response model is constructed, which includes various types of units and AC interconnections in the receiving-end power grid. Subsequently, the multi-machine frequency response model is discretized, and an improved Newton-Raphson algorithm is employed to solve for the system’s minimum inertia value that ensures the frequency response curve of the receiving-end power grid is located at the critical position, based on the constraints of maximum frequency deviation and frequency rate of change. Finally, the effectiveness of the proposed method is verified through a case study of a provincial power grid. The results demonstrate the validity of the proposed method.