Abstract: Abstract: M & A of mining projects is an investment activity full of risks, among which, financial risk is an important factor determining its success. Therefore, it is of great significance on financial warning risk assessment on mining projects' M & A. The major influence factors on financial risk identified by expert investigation method at first; followed by establishing a risk warning assessment index system and defining the index weights by Delphi. Cloud model is introduced to measure the matter element analysis. A financial risk assessment model based on cloud matter element is established to measure the financial risk of mining projects' M & A. The model is then applied to practical cases by calculating the membership degree with Matlab software. The M & A financial risk level of the subjected case is at an ordinary level with yellow warning signal. The evaluation results are consistent with the practice.