With the increase of the proportion of new energy sources, the peak load capacity and frequency stability of power grid have become the main constraint factors for the new energy consumption. This paper presents a comprehensive assessment method of new energy dissipation capacity under the constraints of steady and dynamic equilibrium conditions such as peak adjustment, frequency stability and unit regulation performance. The new energy permeability of the power grid considering the connection line peak adjustment is calculated, and the life loss under the frequent regulation of the unit is calculated by the relationship between the stress and the life to analyze the influence of the new energy acceptance capacity; the frequency stability is regarded as an important constraint condition, then the new energy consumption level under different types of disturbance such as general disturbance and serious fault is analyzed. The analysis reveals the interaction constraints under different factors and improves the systematicness and adaptability of the assessment of new energy consumption capacity. And relevant suggestions are given. This work is supported by National Key Research and Development Program of China (No. 2018YFB0904200).