Abstract: According to the operational mission and performance of tactics and technique for sky-wave over-the-horizon radar(SWOTHR), the operational efficiency evaluation index system for SWOTHR is established. Aiming at the characteristics of involvingmany factors with information fuzzy and uncertainty for operational efficiency evaluation of SWOTHR, an new operational efficiencyevaluation method is pntforward based on cloud model and evidential theory. In the method, discount evidence combination rule isused to combine experts’opinion to ascertain weights and qualitative index values. And then, weights and index values are converted to cloud model and calculated as hierarchies based on cloud calculation rules until getting the target result. The result showsthat the method is useful and feasible, which provides an new idea for operational efficiency evaluation about SWOTHR.