An interpolation method and an interpolation circuit are provided. The interpolation method calculates a difference between values of a first point and a second point and calculates an absolute value of the difference. Then, the absolute value of the difference is used to mix a first function and a second function to obtain a transformation function, which is then used to calculate an interpolation value of an interpolation point between the first point and the second point. Accordingly, the present invention may obtain a result close to high order interpolation without increasing hardware expense.