Cognitive effect is the achievement of cognitive subject’s cognitive purpose.Human’s cognitive effect is prodigiously affected by cognitive frequency in the process of human’s cognition.Vertical frequency of cognition is the number of cognition in unit time.Horizontal frequency of cognition is how many cognitive channels used at one time.Virtual cognition is a whole frequency cognitive style.Cognitive effect can be greatly improved by virtual cognition.This study shows the mathematical model between the cognitive effects and cognitive frequency.